US2796401A - Complex formal lubricating composition - Google Patents

Description

United States Patent COMPLEX COMPOSITION Alfred H. Matuszak,v Westfield, William E. McTurk, Elizabeth,-Delmer L.; C'o'ttle; Highland Park, and David W. Yung,.Westfield,.N. Ji,. assignors' toEsso Research andEngineeringv Companyga corporation of Delaware NoDra'wing; Application November 29, 1952, Serial No. 323,338

11 Claims; (Cl. 2 52-'42) This invention relates to synthetic lubricating compositions. Particularly the invention relates. to synthetic lubricating compositions having outstanding lubricating properties at bothhighlaridlow temperatures and which have the advantage of. leaving. substantially no combustion chamber deposits in" the cylinders of. reciprocating engines. More particularly the inventionre'lates to new and improved synthetic lubricating oils which comprise the formals of, organic compounds: having at least one free hydroxyl group whiclfis' alcoholic in nature, and which contain= a- O['"CH2O(C1LH27LO)1/]ECH2-O linkage, x and'n'heing'i or more an'd'y being 1 or more.

In recent etforts to obtain superior lubricating compositions which have unusual and: specific properties, there have been1develop'ed entirely" new synthetic materials with lubricating properties. In'. general" these new synthetic lubricants are characterized by viscosity properties that are outstandingat both'l'o'w-a'nd high temperatures, especially when compared to mineral oils. These outstanding low and high temperature properties are especially desirable for use in equipment designed to operate over a grea't'ternperature difierential, such as jet engines for aircraft use, combustion engines for aircraft, and the like. It has been found" that mineral lubricating oils are generally undesirable for the lubricating of these engines because of their high and low temperature viscosity limitations.

It'has also been found that synthetic lubricants may be desirable for the lubricating of standard automotive en-. gines. In addition to the versatility of their vi'scosities, the use of some types of the synthetic lubricants investigated havebeen found to result in very low rates of combustion chamber deposit formation, particularly when'used for long periods of time. Low'rates of formation' of' combustion chamber deposits result in increased power factor from fuel, less increase in the octane requirement of the engine, less pre ignitio'n' tendency, and a general overall" improvement" in engine operation. These new lubricants'm'ay also serve to reduce or remove combustion chamber deposits" from an engine already loaded with such deposits. 7

The'pre'sent invention relates to anew type ofsynthetic lubiicating composition which comprises the formalis' of a wide range of organic compounds which contain at least one free' hydroxyl group" and which is alcoholic in nature and which contains at least" three CH"2O"-"1inkages. 7 p v It' has been'gene'rally accepted by the art that most acetals are not of'sufiieie'nt stability to serve as lubri'cat ing compositions; lt h'as'now beeri'foiind, however, and

forms the object'ofthis' invention, that the formals'of organic hydroxy compounds that" contain the linkage --O-'-[CH2 -O (CnHz'nO-l lrCH'z -O where x' and rt are 2. or more and y is lor more have excellent stability and have viscosity prop'erties that make them outstanding lubricating compositions;

A* generic fofmula for'the lubricating compositions of:

thisinventionsmay :he2writt'm asifol'lowsz "ice In the formula A and B represent the organic compounds less the hydroxyl group. x and n represent numbers having a value of 2 or more and y is 1 or more. The radicals may be alike or different and may contain from 1 to 60 carbon atoms. A and B are selected such that the total number of carbon atoms in the formal is between about 20 and 130,. with compounds containing fromv about 25 to carbon atoms being preferred. The organic hydroxy compounds which serve as a source for the radicals A and B will be definedmore in detail below.

For use in reciprocating engines, particularly as a lubricant for automotive engines, a lubricating composition must meet several requirements; In order to form an effective lubricating film and to maintain that film at low and high temperatures it must have certain viscosity characteristics. At low temperatures thelubricant must be sufiiciently labile to flow through: the circulatory system of the equipment and allowmovement of lubricated surfaces without an undue power requirement. A lubricant having an ASTM pourpoint below about 35 F. has suflicient low temperature l'ahilit'y to make it satisfactory in these respects. for general. use. At high temperatures a lubricant must hay'e sufii'cient body or thickness to furnish and maintain a: satisfactory lubricating film. It has been found thata lubricant that is satisfactory in this respect willl have: a viscosity at 210 F. of between about 2 to 60 centistokes, i. c. 32.8 and 280 Saybolt seconds, Universal; T e prevent undue lubricant loss, due to volatility" and general molecular disintegration and to insure againstiexplosion hazards at higher temperatures sometimesencounteredg a lubricating composition should have a flasli point in eXcess-of about 300 F. These requisites are inherent in the term lubricating compositions, as used in. this specification, and the formals of this invention are limited to-those within these operable ranges. The preferred materials, as contemplated herein and as d'escr-ib'ed in the preferred embodiment hereof, -will=have'an.AST-1\'/l pour point below about 15"? F'., a flash point above about 375" F., and will have a viscosity within-the range of' 2.6 to 13 centistokes, i. e., 35 to 70 Saybolt seconds, Universal, at 210 F.

In general it has been found that the above listed properties are a function both of molecular structure and of molecular weight. This fact makes it possible, within certain limits, to prepare compositions having similar low and high temperature properties in a variety of ways and also enables the-manufacturer to tailor a composition to fit a certain setof specifications within rather general limits. This fact also accounts for the large number of organic materials containing alcoholic hydroxyl groups available for preparing thecompositions of this invention.

In general the preparation of the complex formals of this invention is accomplished by methods that require conventional techniques and methods; Three general lines of approach may he followed.

1. The reactantsmay b'e adriibced in the reacting zone and heated to reflux temperature in the presence of an entraining agent such" as' hexane", heptane or the like. After recovery of the water of theory the product is washed free of any acidi'c ca'talysts and stripped free of unreacted components.

2 A second approach is to adinixximoles of the glycol reactant with x1 moles' ofiformaldehydeto obtain the central portion of the complex. formal, i. e'., the portion represented by H@'(CnH2'ho)Z| [@H2 O (E11.H2n())]:cH.

In another reacting zone equalmolesof an alcohol and" 3 to the alcohol hemiformal and heated to reflux temperature. The product, after removal of the theoretical water, is then washed and stripped as above.

3. In this third approach the hemiformal of the chosen alcohol is first made by heating equal moles of the alcohol and formaldehyde. Then to this is added the desired molar proportion of a glycol and formaldehyde and the total mixture heated to reflux temperature to make the hydroxy complex represented by Two moles of this material is then reacted with one mole of formaldehyde to obtain the product which is purified as above.

The materials used to prepare these formals, that is organic hydroxy compounds containingat least one free hydroxyl group which is alcoholic in character, may be selected from the following partial list. Others, of course, may be used.

I. Unsubstituted alcohols Monohydric 1. Aliphatic (a) Methyl alcohol Eb) Ethyl alcohol Propyl alcohol (d) Isopropyl alcohol a n-Butyl alcohol Iso-butyl alcohol Sec.-butyl alcohol 'I'ert.-butyl alcohol n-Amyl alcohol Isoamyl alcohol n-Hexyl alcohol Iso-hexyl alcohol m) 2-ethyl-1-butanol 2-ethyl-1-hexanol Octyl alcohol Iso-octyl alcohol 2-octyl alcohol Iso-nonyl alcohol Decyl alcohol Lauryl alcohol Tetradecyl alcohol Pentadecyl alcohol Octadecyl alcohol Allyl alcohol 1;) Crotyl alcohol z) Oleyl alcohol cm) The terpineols bb) C3 to C2 Oxo alcohols 00) Alcohols derived from the Synol process dd) Alcohols derived from the oxidation of petroleum fractions ee) Alcohols derived from Guerbets reaction f7)1 frillcohols derived from the hydration of o e ns (go) Alcohols derived from the (hh) Mixtures of the above Aromatic (a) Benzyl alcohol b) Phenethyl alcohol (0) 3-phenyl-1-propanol (cl) a-Naphthyl carbinol (e) Cinnamyl alcohol (7) Diphenyl carbinol (g; Furfuryl alcohol (h Cnmic alcohol t) Vanillyl alcohol 1) Piperonyl alcohol B. Polyhydric 1. Glycols M AAAAAAMAAAAMMAAAAMAAAA Oxyl synthesis 1.2-propanediol 1.3-propnnediol 1,3-butanediol e) 1.4-butanediol f) 1.5-pentanediol g) The various polyalkylene glycols, e. g.

1. Polyethylene glycols (a) Diethylene glycol 51;) Triethylene glycol c) Tetraethylene glycol 2. Polypropylene glycols (a) Dipropylene glycol (b) Tripropylene glycol sh) 1,2-cyclohexanedio1 i) Decanedi0l-1.10 2. Other polyhydric alcohols (11) Glycerol (b) 2hydroxymethyl-2-methyl-propanedlol-I,3 (c) Pentaerythritol I v d orbitol e) Dipentaerythritol f) Dulcitol Trimethylol propane 'letramethylol cyclohexanol t) Benzotrimethylol II. Substituted alcohols Monohydric 1. Aliphatic (a) Halogenated alcohols 1. Ethylene chlorohydrin 2. Trlfluoro ethanol 3. Propylene chlorohydrln 4. The various chloro-substltuted monoethers of polyalkylene glycols Ethanolamine 2-amino propanol 2-m'troethanol 2-nitropropanol 2-nitrobutanol The various glycol monoesters, e. g. 1. Ethylene glycol monoacetate 2. Propylene glycol monobutyrate Butylene glycol monolaurate Polyethylene glycol monoesters Polypropylene glycol monoesters Polybutylene glycol monoesters he various glycol monoethers, e. g.

Ethylene glycol mono-methyl ether Propylene glycol mono-butyl ether Butylene glycol mono-lauryl ether Polyethylene glycol mono-others Polypropylene glycol mono-others Polybutylene glycol mono-ethers Polytrimethylene glycol mono-ethers (i) The various glycol mono-formals, e. g. the

mixed formals of glycols and alcohols (j) Hydroxy alkyl cyanides 1. Ethylene cyanohydrln 2. oz-Hyroxy lsobutyronltrile (k) Ethanol morpholine 2. Aromatic (a) p-Methoxy benzyl alcohol (b) The various chlorobenzyl alcohols (c) The various nitrobenzyl alcohols (11) 2-anilino ethanol B. Polyhydric 1. Glycols (a) Halogenated glycols, e. g.

1. 3-chloro-1,2-propanediol 2. 2-chloro-1,3-propanediol (b) Nitroglycols, e. g.

1. 2-nitro-1,3-propaned1ol 2. 2-nitro-2methyl-propanediol-l,3 3. Trimethylol nitromethane (0) Amino glycols 1. 2-amino-1,3-propanediol 2. 2-amino-2-methyl-1,3-propanediol 3. Diethanol amine 4. Trimethylol aminomethane C. Other hydroxy compounds 1. Esters of hydroxy acids (a) The varlous lactate esters (b) The various glycolate esters (c) The various hydroxy stearate esters 2. Carbonyl substituted alcohols (41) Hydroxy ketones, e. g.

1. Hydroxy acetone (b) Hydroxy aldehydes, e. g.

1. a-Hydroxy adipaldehvde 2. B-Hydroxy propionaldehyde Particularly desirable organic hydroxy compounds for use in this invention are those highly branched chain aliphatic alcohols prepared by the OX0 synthesis. This Oxo synthesis may be described as being the catalytic reaction of an olefin with carbon monoxide and hydrogen. The reaction occurs at temperatures in the order of 300400 F., at pressures in the range of about 1000 to 3000 p. s. i., in the presence of a suitable catalyst, ordinarily a heavy metal carbonyl such as cobalt carbonyl. The resulting aldehyde is subsequently hydrogenated to a primary alcohol. This process is described in U. S. Patent No. 2,327,066 issued to Roelen in 1943.

In general the oxygenated group in a product from an olefin by the Oxo process is thought of as becoming attached to an unsaturated carbon which holds at least one hydrogen atom. In those cases Where the carbon monoxide attacks a saturated carbon atom, it must be assumed either that that carbon has become unsaturated prior to reaction by a shift of a hydrogen atom or that the attack is directly on a carbon atom that is truly saturated. For example, Z-butene has been reported to e s s z e give l-pentanol and Z-methylbutanol in equal quantities,

hydrogen is attached to the unsaturated carbon atoms and the attack of carbon monoxide must either be on a rearranged olefin or on a saturated carbon atom.

It has been found that particularly desirable alcohols for the formation of the formals of this invention can be prepared by the application of the 0x0 synthesis to polymers and copolymers of C3 and C4 monoolefins. These monoolefins are. readily available in petroleum greener refinery streams and processes for their conversion to liquid copolymers have been worked out by the art. One such process, known as U. 0. P. polymerization, consists of passing the olefin-containing stream in liquid phase in contact with an acid catalyst comprising phosphoric acid impregnated on kieselguhr. Other acidic catalysts, such as phosphoric acid or copper phosphate impregnated on silica gel, sulfuric acid, Friedel- Crafts catalysts, activated clays, silica-alumina, copper pyrophosphate, etc., may be used. Suitable conditions when employing phosphoric acid catalysts of the U. 0. P. type are temperatures of 300 F. to 500 F., pressures from 250 to 5,000 p. s. i. and feed stocks comprising refinery streams containing propylene and mixed butylenes. Suitable feed stocks, for example, may contain from to 60 mol percent propylenes, from 0.5 to 15 mol percent butylenes, and from 0.1 to 10 mol percent isobutylene, the remaining being saturated hydrocarbons. Other suitable feed stocks are the dimer and trimer of isobutylene.

The prefenred Ox'o alcohols employed in forming the formals of this invention are those having from 8 to carbon atoms derived from olefin copolymers having from 7 to 19 carbon atoms. In preparing these Oxo alcohols the desired olefin fraction is segregated from the crude olefin polymer product by fractionation.

The following table, for example, shows the structure and percent composition of Ca OX0 alcohols prepared from a. C7 olefin stream which had been fractionated from the products obtained by the phosphoric acid polymerization of refinery gas streams containing propylene and mixed nand isobutylenes.

As was stated above, the formals of this invention, hereinafter referred to as complex form'als, may be considered to have the following general formula:

In the formula A and B represent radicals derived from organic compounds by removal of one reacting h'y'droxyl group. In the formula x and n are 2 or more and y is one or more. The radicals represented by A and -B may be alike or different and may contain fromxl to 60' carbon atoms. The sum of the carbon atoms in -the molecule should be between 20 and 130 and .pre'ferablyzbetween about and 100. 1.

The grou of organic compounds that satisfy th'eeonditions of the above generic formula and that are used to build the preferred compounds according to the concept of this invention are monohydric alcohols, glycols, and organic acids. These compounds may be advantageously combined with formaldehyde to form molecules having the following type formulas, words instead of structures being given to show the components of the complex formals.

Alcohol-(formaldehyde-glycol Glycol- (formaldehyde-glycol a:

Glycol monoester-(formaldehyde-glycol)a Glycol monoeth'e'r-(formaldehyde-glycol)m In all formulas given above x represents a Whole number greater than 11. The acids which may be used to prepare the glycol monoesters may be selected from the following partial list:

Acetic Methoxy propiouic Propioni'c Ethoxyethox acetic Butyric v Mono-Z-ethyl exyl adipate 2-ethyl bu'tyi-ic Mono-Cs 0 x0 sebacic Caproi'c Ca C2o 0x0 acids, including bottoms acids 2-ethylhexanoic Ac ds derived from petroleum fractions Caprylic by oxidation Pelargoni'c Acids derived from alcohols and/or alde- Capric hydes by caustic fusion Laurie Naphthenic acids Myristlc Glycolic acid Oleic Lactic acid Stearic Hydroxystearic acid This concept of the instant invention may be illustrated as follows:

EXAMPLE I of n-butyl Carbitol-(CHzO-tripropylene glycol); i. e.

n-ctin ocrncHz)2ocuzocsneocansocgneonn The hemiformal of n-butyl Carbitol was made by heating 81.1 g. /z mole) of the Carbitol with 15.1 g. /2 mole CH2O) of paraformaldehyde, 200 g. of heptane and 2 g. of NaHSO4 at 65 C. for half an hour.

The polyforrnal of tripropylene glycol, i. e.

was made by refluxing 384.5 g. (2 moles) of tripropylene glycol, 45.5 g. (1.5 moles CHzO) of paraformaldehyde, 200 g. of heptane and 3.2 g. of NaHSO4 for minutes at 89 to 104? C. The volume of the water layer was 28 cc. (theoretical is 27 cc.). To minimize simple formal formation'the' hemiformal of n-butyl Carbitol was added dropwise over a period of 70 minutes to the refluxing solution of the polyformal of tripropylene glycol. After the hemiformal was added refluxing at 102 C. was continued for an additional 30 minutes. The volume of the water layer was now 37 cc. (theoretical is 36 cc.). The catalyst was removed by decanting. The mixture was then washed with three 100 cc. portions of 5% NazCOa and two 100 cc. portions of water. After stripping -off the solvent and unreacted material, the product boiling above 140 C. at .2 mm. (kettle temperature of 231 C.) gave the following inspections:

Viscosity, cs. at F.:

Preparation 210 n. 50.86 (235 SUS) 100 423.1

0 -1"; 59,700 Viscosity index p Pour point, F '25 Hydrogen combustion test: Carbon, 1.1 mgs; varnish, 0.7 mg.

' EXAMPLE II Preparation of polyethylene glycol pol'yfo'rinal i. e.,

I HO (CH2CH2O) 6.4 [CH2(OCH2CH2 GI-tOIIZrH This olyfor mal was made by heating 300g. (1 Thole) of polyethylene glycol of a molecular weight of about 300, 30 g. ("l-mole onto ofparaforma'ldehyde, 200 g.

Polyethylene Polytorrnal of Glycol 300 PE G-300 Viscosity, Cs. at F.:

210 5.68 (44.79 SUS) 36.40 (170.7 BUS).

'. 34.24 (159.8 SUS) 290.7 (1343 SUS).

116 132. +30. Flash Point, F 400 360. Fire Point, F 445 460 Alcohol-Z-formaldehyde-alcohol Alcohol-Z-formaldehyde-glycol monoester Alcohol-Z-formaldehyde-glycol monoether Glycol monoester-Z-formaldehyde-glycol monoester Glycol monoester-Z-formaldehyde-glycol monoether Glycol monoether-Z-formaldehyde-glycol monoether By substituting a hydroxy acid monoester such as lactates and glycolates, another series of compounds may be prepared as follows:

Hyd'roxy monoester-Z-formaldehyde-hydroxy monoester Hydroxy monoester-Z-formaldehyde-alcohol Hydroxy monoester-Z-formaldehy-de-glycol monoether Hydroxy monoester-Z-formaldehyde-glycol monoester It will be seen that the above mentioned complex formals all are included under the generic formula:

wherein A and B may be the same or diiferent and are selected from the group consisting of organic radicals containing from 1 to 60 carbon atoms which corresponds to organic compounds containing a hydroxyl group that is alcoholic in nature and wherein x and n are whole numbers greater than 1 and y is 1 or more.

This concept of the invention may be further illustrated by the following examples:

EXAMPLE III Preparation of C13 Oxo Alcohol-(CHzO-Tripropylene Glycol)3CI-I zO--C1z Oxo Alcohol i. e.,

C13H27O [CH2O (CaHeO 3] 3CH2-OC13H2'1 The central portion, i. e.,

H OCaHs) OCH2 OCsHe) s-OCHz OCsHs) 30H of this polyformal was first made by refluxing 288 g. (1.5 moles) of tripropylene glycol, 30 g. (1 mole CHzO) of trioxymethylene 300 g. of heptane and 5.5 g. of catalyst (NaHSO4) for 40 minutes at 89 C. to 100 C. The volume of water collected was 19 cc. (theoretical is 18 00.). The reaction mixture was cooled to 70 C. at which point 200 g. (1 mole) of C13 Oxo alcohol and 30 g. (1 mole CHaO) of trioxymethylene were added. The reaction mixture was then heated at reflux temperature 90103 C. for 30 minutes during which time 19.5 cc. (theory is 18 cc.) of water was collected.

. The reaction product was decanted from the catalyst and then washed with 150 cc. of NazCOa solution and finally with two 100 cc. portions of water. The material was then stripped free of the solvent and light ends. The material boiling above 152 C. at 0.3 mm. pressure and consisting of the 14100% fraction had the following proper-ties:

Viscosity, cs. at F.:

0 4657 Viscosity index 132 Pour point, F. -45 Flash point, F. 420 Fire point, F. 455

Hydrogen combustion test: Carbon, 1.3 mg.; varnish,

The clean burning characteristics of this reaction prodnot indicate that it would give essentially no octane requirement increase if it were used as an automotive crankcase lubricant.

EXAMPLE IV Preparation of C13 Oxo Alcohol-(CHzO-Tripropylene Glycol)2-CH2O-C1a Oxo Alcohol This complex formal which is similar to that prepared above was made to obtain a lower viscosity material. The C13 0x0 alcohol (520 g., 2.6 moles), 117 g. of paraformaldehyde (3.9 moles CHzO), 200 g. of heptane and 3.1 g. (0.25% of NaHSO4 catalyst were heated to 55 C. for 45 minutes. To this hemiformal of C13 Oxo alcohol was then added 500 g. (2.6 moles) of tripropylene glycol and the mixture heated to reflux. After three hours the temperature had risen from C. to 118 C. and 73 cc. of water had been collected. (The theoretical amount of water is 70.2 cc.) The material was light tan in color indicating that the small catalyst concentration (0.25 was helpful in not causing excessive discoloration which occurs when the usual 1% catalyst is employed. The reaction product was separated from the crystalline catalyst and washed with three cc. portions of saturated Na2CO3 solution and then with three 100 cc. portions of water before stripping of the heptane and small amount of water. The product boiling above 153 C. at 0.2 mm. mercury pressure and consisting of the 6 to 100% fraction had the following properties.

Viscosity, cs. at F.

210 5.82 100 33.82 0 2286 -40 80,000+ Viscosity index Pour pount, F. 50 Flash point, F. 390 Fire point, F. 430

Hydrogen combustion test: Carbon, 0.8 mg; varnish,

EXAMPLEV Preparation of n-Butyl- (OCaHs 2O CHzO-Polypropylene Glycol 2--CH2O( OCaHe) 2 n-Butyl The preparation of this complex formal was accomplished according to the description of Example IV.

The material obtained boiling above 161 C. at 0.3 mm. had the following properties:

Fire point, F. 345

:9 The fraction of thekprod ct boiling above .1 88 C. at 0.2 mm. had the following properties:

Viscosity at 210 F. 5.39 100 F. 29.46 0 1709 40' F. 55,849 Viscosity index 129 Pour point, F. 60 Flash point, F. 350 Fire point, F. 390

EXAMPLE VI Preparation of C13 Oxo .Alcohol-'(CHzO-Tripropylene Glycol)2.3-CH2OC1s 0x0 Alcohol Two moles C13 Oxo alcohol, 3.7 moles of formaldehyde, as paraformaldehyde, and 2.3 moles of tripropylene glycol were admixed with 300 g. heptane rand 1.5 g. of sodium acid sulfur. The mixture was heated to reflux temperature until the theoretical water was evolved. The product was then decanted from the catalyst and washed with 100 cc. portions of sodium carbonate three times; it was then washed twice with 100 cc. portions of water and then "filtered. The material was then stripped to 176 C. vapor temperature at 10 mm. The product had the following properties:

Viscosity at 210 .F. .8.06 (52.6'SUS) 100 F. 47.81(22l.3SUS) A 0 3491 -40 F. 110,000+ Viscosity index 136 Pour point, F. -50 Flash point, F. 425 Fire point, F 460 EXAMPLE VII Preparation of C13 Oxo Alcohol-CH2O(Triethylene Glycol-CHzO') 2C13 Oxo Alcohol 400 g. of C13 Oxo alcohol .and 6.7 .2 g. of formaldehyde was admixed and heated with 2.4 g. of NaHSOq. in the presence of 240 g. of 'heptane. The mixture was then heated to 55 F. for approximately 25 minutes. To this mixture 300 g. of triethylene glycol was added and this mixture heated to 113 C. for approximately one hour. At this point 33.6 g. additional formaldehyde was added to the reacting mixture. This mixture was then heated to 115 C. for an additional hour. At the end of this period 60 g. of water had been removed (54 g. theoretical).

This product was purified in the manner similar to that of Example VI above and stripped to 210 C. vapor temperature at 9.0 mm. pressure.

This product had the following properties:

Viscosity at EXAMPLE VIII Preparation of C13 Oxo Alcohol0(CH2O-Pentanedioll,5)3CH2-O-C13 Oxo Alcohol This product was prepared as described in Example VII above except that the glycol was pentanediol-1,5 instead of triethylene glycol. The product was stripped to a vapor temperature of 182 C. at 10 mm. pressure.

The properties of this product are as follows:

Viscosity at 210 F 2.28(67.4 SUS) F .'75.56'(349i3"SUS) 0 4,035 40 F -Q;

Viscosity index 143 Pour point, F ---35 Flash point, F 440 Fire point, F -1485 The complex formals as describedherein may serve as the lubricant base for grease compositions. These syntheticlubricants may be thickened to stable grease structures with conventional grease forming soaps such as lithium soaps of high molecular weightsubstantially saturated fatty acid, the n-acyl p am'ino phenols, silica gels, treated bentinites and the like. Oxidation inhibitors, rust inhibitors, tackiness agents and other grease addition agents may be added to the complex formal greases. The soap complexes known to the artmade by using low molecular weight acid salts .may also be used in preparing these grease compositions. .If desired the complex formals of this invention may be blended with mineral oil or other synthetic lubricants such as simple bis-formals, complex esters, di-esters, phosphates, siloxanes, silicates, phosphonates and the like and a grease composition which incorporates the desirable characteristics of the blends may be prepared by conventional techniques.

The following illustrates the procedures used in preparing the grease compositions generally described above:

Formulation Preparation A very good dispersion of the soap in the synthetic oil was obtained by heating the soap and oil to 450 F. with stirring. During the early stages of heating the mass swelled. The phenyl a'lpha-naphthylamine was added and the mass was pan cooled. The resulting product had an excellent grease structure and had a dropping point of 379 F.

To summarize briefly, this invention relates to new compositions of matter which have outstanding utility as synthetic lubricating compositions. The materials contemplated may be broadly described as being complex formals of organic materials containing at least one hydroxyl group that is alcoholic in nature. By complex formal is meant materials containing more than 2 formal linkages. The structure of the formals of invention may be described as one corresponding to the formula:

where x and n are whole numbers greater than 1 and y has a value of 1 or more. In this formula A and B are organic radicals containing from 1 to 60 carbon atoms which are derived from organic materials containing at least one hydroxyl group that is alcoholic in nature. A and B may be alike or different and the total number of carbon atoms in the molecule should be between about 20 and 130, preferably between about 25 and 100. The compounds that are especially preferred and that are considered to be the preferred embodiment of this invention are those materials that have a kinematic viscosity at 210 F. within the range of from 2 to 60 centistokes, an ASTM pour point of at least as low as 35 F., and a flash point of at least 300 F.

The formals of this invention are useful as plasticizers,

solubilizers, grease bases, insecticides, weed killers, rust preventives, solvents, .dewaxing aids, detergents, and as raw materials for many other industrial applications, such as household -detergents, fumigants, etc. These new synthetic lubricating oils may be admixed with other lubricating oils, naturally occurring or synthetic, either as concentratesor as finished blends. They are compatible and may bev blended with the well known lubricant addition agents such as viscosity index improvers, pour point depressors, detergents, rust inhibitors, antioxidants, and the like.

What is claimed is:

1. As a synthetic lubricant, a complex formal having an ASTM pour point below about 35 F., a flash point above about 300 F., and a kinematic viscosity at 210 F. within the range of from 2 to 60 centistokes, said formal corresponding to the formula wherein A and B are selected from the group consisting of hydrocarbon and substituted hydrocarbon radicals containing from 1 to 60 carbon atoms wherein at and n are integers having a value of at least 2 and y is an integer having a value of at least 1, the total number of carbon atoms in the molecule being between and 130.

2. A synthetic lubricant according to claim 1 wherein A is derived from monohydric alcohol and wherein B is derived from a glycol.

3. A synthetic lubricant according to claim 1 wherein A and B are organic radicals derived from Ca to C20 branched chain alcohols and wherein n, y and x are 3.

4. As a synthetic lubricant, a complex formal having the formula wherein A and B are organic radicals derived from C8 to C20 alcohols and wherein x and n are numbers having the value of 2 or more and y is an integer having a value of at least 1, said formal being formed by reacting together x.y moles of a glycol with x-I-l moles of formaldehyde and 2 moles of an alcohol containing from 8 to 20 carbon atoms, said formal having an ASTM pour point below about +35 F., a flash point above about 300 F., and a viscosity at 210 F. within the range of from 2 to 60 centistokes, the total number of carbon atoms in the molecule being between about to 100.

5. A synthetic lubricant according to claim 4 wherein said alcohol isa highly branched chain aliphatic alcohol of 8 to 20 carbonatoms.

6. A synthetic lubricant according to claim 4 wherein said glycol is tripropylene glycol.

7. A synthetic lubricant according to claim 4 wherein said glycol is a polyethylene glycol.

8. A synthetic lubricant according to claim 4 wherein said alcohol is a highly branchedchain aliphatic alcohol of 13 carbon atoms alcohol and wherein x, n, and y are 3.

9. A synthetic lubricant according to claim 4 wherein said alcohol is an ether alcohol, wherein said glycol is a polypropylene glycol of a molecular weight of about 150 and wherein x is 2.

10. A synthetic lubricant according to claim 4 having an ASTM pour point of below l5 F., a flash point in excess of 350 F. and viscosity at 210 F. of from 2.6 to 13.0 centistokes.

11. As a synthetic lubricant, a complex formal of the formula wherein A and B are selected from the group consisting of hydrocarbon and substituted hydrocarbon radicals containing from 1 to carbon atoms and wherein x and n are numbers having the value of at least 2 and wherein y is a number of at least 1 thickened to a grease consistency with a lithium soap of a high molecular weight fatty acid, said complex formal having an ASTM pour point below about +35 F., a flash point above about 300 F., and a viscosity at 210 F. within the range of from 260 centistokes, the total number of carbon atoms in said formal being between about 20 to 130.

References Cited in the file of this patent UNITED STATES PATENTS 2,350,350 Gresham June 6, 1944 2,379,703 Geltner July 3, 1945 2,397,602 Gresham Apr. 2, 1946 2,436,347 Zimmer et al Feb. 17, 1948 2,473,994 Gresham June 21, 1949 2,594,341 Owen et al. Apr. 29, 1952 OTHER REFERENCES Wender and Orchin: Critical Review of Chem. of 0x0- Synthesis, Bur. of Mines, R. I. 4270, June 1948, pages 6 and 9.

Claims (2)

1. AS A SYNTHETIC LUBRICANT, A COMPLEX HAVING AN ASTM POUR POINT BELOW ABOUT 35*., A FLESH POINT ABOVE ABOUT 300* F., AND A KINEMATIC VISCOSITY AT 210* F. WITHIN THE RANGE OF FROM 2 TO 60 CENTISTOKES, SAID FORMAL CORRESPONDING TO THE FORMULA

11. AS A SYNTHETIC LUBRICANT, A COMPLEX FORMAL OF THE FORMULA