US3177146A

US3177146A - Fire-resistant hydraulic fluids

Info

Publication number: US3177146A
Application number: US145754A
Authority: US
Inventors: Charles E Francis
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1961-10-17
Filing date: 1961-10-17
Publication date: 1965-04-06
Anticipated expiration: 1982-04-06
Also published as: CH434533A; GB967785A; NL284405A

Description

. 3,177,146 FIRE-RESISTANTHYDRAULIC FLUIDS CharlesE. Francis, Martinez, Calif., assignor to ,ShellOrl Company, New York, N.Y., a corporation of Delaware N o Drawing. Filed Oct. 17, 1961, Ser. No. 145,754

' 'Claims. (Cl. 252--75) v United States Patent 07 their poor stability and their inability-to pass fire-resistant requirements for which such fluids are primarily used.

In colliery equipment such as various hydraulic machinery, e.g., winder brake mechanism and wagon tipper to hydraulic jacks, pit props and roof bar straighteners, mechanical loaders and various other fluid drive mechanisms which are subject to load, shock and vibration, it is essential that the hydraulic fluid employed therein function properly and efliciently without the danger'of being flammable or toxic.

A variety of so-called fire-resistant fluids are commercially available such as phosphate ester base fluids, but

these have been found to possess poor low temperature viscosity-temperature properties, and they are toxic. Water-glycol solution or various water-oil emulsions have been found to have a tendency to form deposits and cause wear under high pressures and are costly. Also most emulsifiable oil concentrates when emulsified with hard water tend to form deposits whichadversely affects the equipment. 7

It is an object of this invention to provide a composition which can be emulsified readily on the job to yield a fire resistant hydraulic fluid having good lubricating properties. Another object is: to provide a fluid which after emulsificat'ion I is a satisfactory lubricant for colliery hydraulic equipment, which is stable, non-toxic, fire-resistant, resistant to deterioration, inhibits corrosion and not cause wean Still another object of this invention is to provide a'water-mineral oil emulsion usable as lubricants and fire resistant hydraulic fluids for various equipment used in colliery hydraulic equipment. Still another object of this invention is to provide an oil concentrate which is readily emulsifiable with soft or hard water and capable of forming water-in-oil emulsions which are stable over a wide temperature range.

These and other objects are accomplished in accordance with this invention by providing a water-in-oil emulsion which comprises from about to, about 45% of water phase and from about 55% to about80% of oil phase, the emulsion containing three essential additives namelyftw'o particular types of dissimilar non-ionic surface active agents and a water-soluble polymeric derivative of an acrylic acid represented'by the formula:

ota-. 1 ra t 1 md where R is hydrogen or. a C 4 alkyl radical, R and R" may be hydrogen or lower alkyl radicals of up to 8 carbon atomsor they may be. mixtures of hydrogen and a lower alkyl radical, M is a cation such asanalkali metal such as lithium, sodium or potassium, or ammonia or an organic base, x is a positive integer, y may be zero 3,177,146 I Patented Apr fi, 1965 or a positive integer and z may be zero or a positive integer, the molecular weight of the polymer varying from at least 1000, up to 500,000, preferably between 25,000 and'300,000. Instead of a polymer as represented by (I) a mixture of water-soluble homopolyrner's containing the desired groups :R CH3C O OM (II and I l- R L lg NRRL (III,

or polymers of (II) or (III) admixed with polyacrylic acid (IV).

The two non-ionic surface agents which are added to the mineral oil are (1) a monoester of a long chain fatty acid having at least 8 carbon atoms and an inner'ether of aliphatic polyhydric alcohols such as hexahydric alcohols and (2) a polyalkyleneoxy phenoxy alkanol. Each of these additives must be present in critical amounts of which the monoester (1) is used in amounts ranging from 1% to 4%, preferably from 1.5% to 3% and the polyalkyleneoxy phenoxy alkanol (2) isused in amounts ranging from 0.5% to 3%,preferably from 1% to 2%.

In the monoester non-ionic surface agent the inner ether alcohol is prepared by partially dehydrating polyhydric alcohols whichv results in the conversion of the polyhydric alcohol to inner ether polyhydric compounds having '1 or 2 ethers and 4 to 6 hydroxyl groups in the molecule in the manner described-in US. Patent 2,322,820. Compounds of this type, are exemplified by sorbitan, mannitan, xylitan, dulcitan, etc. Fatty acids which are used to form the monoesters of the inner ether polyalcohols are saturated a-nd unsaturated fattyacidshavingat least 8 carbon atoms, preferably from 12 to 18 carbon atoms, such I ;aslauricgstearic,.oleic, linoleic, ricinoleic acids and the '.like.., Monoesters of this type include'sorbitan monolaurate, sorbitan monostearate,.sorbitan monoole'ate, sor- .bitan monoricinoleate, mannitan monolaurate, mannitan monooleate, and mixtures thereof. Compounds of this type are available commercially as Span 20, 60 or from the Atlas Powder Company.

' The second essential additive is an oil-soluble alkyl phenoxy polyalkylene glycol having the formula propanol, and mixtures thereof.

The water-soluble copolymer or mixtures of homopolymer as defined by the above formulas can be prepared by any suitable means well known to the art. .Thus the copolymers of Formula I can be prepared by copolymerizing a mixture of acrylic acid and acrylamide and reacting the copolymer with an alkali metal hydroxide to convert wholly or in part the acid groups to alkali metal carboxylate groups or an acrylamide may be polymerized and hydrolyzed inthe presence'ofapolymerization catalyst and alkali metal hydroxide. The catalysts include inorganic or organic peroxides, or per-acids orazo catalysts .suchas V hydrogen peroxide,.. diethyl peroxide, benzoyl peroxide,

sodium or. potassium persulfiate, azocatalyst, e.g., alpha! -alphaJ-azodiisobutyronitrite, etc. and the-alka'li metal hydroxide. includes sodium, potassium and lithium hydroxparts o-f water and (b) aqueous mixture of about 400 parts 900 parts water and reacting the two (a) and (b) at about 80 C. in the presence ofan inert atmosphere. The product'contained a mixture of acrylamide and sodium .car-, boxyl groups and had ,a viscosity-of 12,000-2l,000 cps.

Other water-soluble polymers in the'molecul-ar weight range of 5000-400,000 include sodium polyacrylate, so-

.ides. Thus;asodium'polycarboxylate polyac rylamid'e (X) was' prepared by admixing solutions of (a). aqueous :solutions containing about 5500' parts of acrylamide and 4000.

of sodium hydroxide, 70 partsof potassium persulfate and dium polymethacrylate, sodiumpolyacrylate-po1yacrylic acid, potassium .polyacrylate-polyacrylamide, potassium and homopolymer of acrylic acid (60/40), mixture ofpolymer (X) and polyacrylic acid (Y) and the like.

Although water-soluble polymers of the above typeare useful as thickeners, as polyelectrolytes, as fluocculants,

etc., their use in .hydraulicsystems with which the present invention is concerned is new, novel and unexpected. The

polymers are dispersed in the waterphase of emulsions of water containing the polymer to] desired degree.

In addition to the above three essential additives it is preferred to use in such compositions small amounts of:

from about 0.01% to about 2%,preferably from about 0.2% to about 1% optional'additives which include antioxidants and antiwear agents.- The-antioxidants include phenolic, amine and/or metal thiophosphate compounds.

The phenolic compounds are illustrated by the "alkyl phenols, e.g., di-and trialkyl'phenols, for instance, 2',4-, 2,3-

3,4-, and 2,6- and 3,5-diamylphenol; 12,4-dimethyl-6-tert. v butylphenol, 2,6-ditert.butyl 4-methylphenol. The amines are illustrated in ar ylamines such as phenyl-alpha-naphthylamine or phenyl-beta-naphthylamine. The metal thio phosphates are illustrated by alkaline earth metal thiophosphates, e.g., calcium or zincdimethyl cycl'ohexyldithiophosphate. The. antiwear agents are sulfur-containing compounds such as oil-soluble polychlo'ro hydrocarbyl thiocarbonate esters, e.g., polychloronaphtha methyl xanthate marketed by Monsanto Chemical Co. under .the

name ,SantopoidS and characterized by sp. gr. 1.19 at. 60/60 'F.,fiash point 250 F., viscosity 63 cs. at, 100

F., sulfur 11%, chlorine 31%. Thi'ocarbonates ofithis type are prepared by reacting a chlorinated petroleum I naphtha with an alkali metal (potassium) amyl dithiocarg bonate; organic sulfides such as dibenzyldisulfide' or di- 'chlorodibenzyl disulfide. Dyes and antifoaming agent can Oil-soluble be added. to composition ofv this invention. dyes include naphthol yellow, Sandoz yellow, methylene blue, .aliz'arin compounds, etc.', 'while anti-foaming agents include silicone polymer (DC-200 fluids ranging in vis cosity in centistokes from 100 to 1000 at 250 C.) or-sili cone type A fluidmade by Dow-Corning Co. and described in US. Patents 2,563,588and 2,662,055and mixtures thereof. 7

The oil may beentirely a hydrocarbon oil of wide -vis cosity range, e.g'.,from less than SOSUS atlOO F. to 15 0 SUS.at 210 F. Oils of this type can :beobtain'ed from various crudessuch as parafiinic, naphthenicor mixed basecrudes; refined oi-ls in the lubricating oil viscosity range are preferred. On the other hand, the hydrocarbon ,ing or after it is prepared'is not necessary. If desired, the emulsion canbeput through a homogenizer to insure 7 shipping costs can bereduced.

oil may be blended with fixed oils such as castor oil, lard oil and vthe'like and/or with synthetic lubricants suchas polymerized olefins, organic .estersyofi organic and inor- I ganic acids, e.g., di-Z-ethylhexyl sebacate, dioctyl phthal-- ate, trioctylphosphate; polymeric tetrahydrofuran, polyalkyl silicone polymer,- e.g., dimethylsilicone polymer and the like. Where'mixtures or blends are used the hydrocanbon oil such .as atmineral-lubricatingzoil is always present in the predominant amount such as from 60% to about of the oil :blend. 1' Astraightmineral lubricating oil, havingga viscosity index of at least 50. and ranging inviscosity at 1009--F.

"of from '75 to 400 SUS, usually preferred. When it is derived from-a lubricating .oil stock of lowviscosity index it is readily provided-as raflinate in a selectivelsolvent extraction process as is well understood in thejart. The

emulsion can be preparedby adding. the required amount of water containing the polymeric compound as described to an oil,containing theother two essential additives, while constantly stirring the mixture. Heating the; emplsion dura more, stable emulsion- Instead of making the finished emulsion, the :oil concentrate, composition can be prepared and .thejre'quired. amount of water containing a polymeric compound as described added whenthe emulsion lubricant is ready .foruse. In ,this way storage and Illustrative examples of:minera1 oilbases of this invention which are emulsified ,iwith ,from about 20% 'to about 45%, preferably fromaboutt 30% to about 40% of water. containingpolymeric acylo compound to form a stable fire-resistanthydraulic fluid. are presented below.

Composition A1 Percent wt. Sorbitan-monooleate :2 Diisobutylphenoxy(ethoxyhethanol 1 Mineral oil Balance Composition B:

Sorbitan monostearate 2 Diisobutylphenoxy(ethoxyhethanol 1 Mineral oil Balance Composition C:

Mannitan monooleate a. 3 Diisobutylphenoxy(ethoxy) ethanol 1 Mineral .oil Balance Composition -D: 7 i

Sorbitan monooleate f 2 Diisobutylphenoxy(ethoxy) ethanol 1 2,6-ditert.butyl-4-methylphenol 0.2 'Phenyl-alpha-naphthylamine f 0.1 Mineral oil Balance Composition E1 V V Sorbitan monooleate I 2 Diisobutylphenoxy(ethoxy) ethanol l 2,6-ditert.butyl-4-methylphenol 0.2 Phenyl-alpha-naphthylamine r 0.1

Mineral oil' ,Balance Composition F: V

Sorbitanrnonooleate 2 Diisobuty1pl1enoxy,(ethoxy) ethanol 1 4,4'-methylene(2,6 ditert.butylphenol) 'Phenyl-alpha-naphthylamine. a 0.1

Mineral. oil Balance Compo'sitionG:

Diisobutylphenoxy(ethoxy) ;ethanol 1 4,4,'-methylene(2,6-ditert.butylphenol) i 0.2 Phenylralpha-naphthylamine i 0.1 Mineral oil Balance pm a...

The finished emulsion fluid is prepared by slowly adding to the oil base compositions such as A, B, C, D, E, F, G or H, from 20% to 45 based on the total composition, an aqueous base, such as water which contains 0.1% sodium polyacrylate-polyacrylamide (X) for compositions A, B and F, 0.05% sodium polyacrylate-polyacrylamide (X) for composition D, 0.1% potassium polyacrylate-polyacrylamide (X) for composition C, 0.2%

' polyacrylic acid +01% sodium polyacrylate-polyamide' (X) for composition'E, 0.2% ammonium polyacrylatepolyacrylamidetX) for composition G and 0.1% lithium polyacrylate-polyamide (X) for composition H. The water base may or may not contain 0.014% of a corrosion or wear inhibitor such as water-soluble inorganic nitrites, nitrates, chromates, phosphates or water soluble low molecular weight salts such as alkali metal or alkaline earth metal (Na, K, Ca, Ba) acetate or propionate. The water-in-oil emulsion can be mixed by any suitable means such as by air agitation, propeller agitation or by passing through a colloid mill until a homogeneous stable water-in-oil emulsion is formed. For economical reasons, the water is added to the oil in desired amounts at the 7 time the emulsion is to be used, although a stable waterin-oil emulsion can be prepared and stored for a moderate period. i

A'finished water-in-oil emulsion (Composition-l) wasprepared by admixing 60% of composition D with 40% water and the mixture was passed through a colloid mill until a stable homogeneous water-in-oil emulsion was formed.

Other finished compositions include:

Percent Ca petroleum sulfonate and/ or Ca C alkyl salicylate ignited after 5 cycles.

I claim as my invention: 1. A water-in-oil emulsion lubricant and hydraulic fluid which is from about 20% to about 45% water: phase consisting essentially of water and from about 0.01% to about 2% of a water-soluble polymeric compound having a molecular weight in the range from 1,000 to 500,000

and having the formula R i FF IE i F i -o1-r,- Y

OM x OH y where R is a radical selected from the group consisting of hydrogen and a C alkyl radical, R and R" are radicals selected from the group consisting of hydrogen and an .alkyl radical of up to 8 carbon atoms, M is a cation selected from the group consisting of an alkali metal, ammonium, and an organic base, x is a positive integer and y and 2 may be zero and positive integers, and from about 55% to about 80% oil phase, the oil phase being essentially a high viscosity index mineral oil having a viscosity in the range from 50 SUS at 100 F. to 150 SUS at 210 F. containing (1) from about 1%, to about 4% of a monoester of a long chainfatty acid having'at least 8 carbon atoms and an inner ether of an aliphatic polyhydric alcohol having 1-2 ether and 4-6 hydroxyl groups,

1 Water contains the corresponding water-soluble polymeric additive noted above used to blend with Compositions A to H, respectively and in amounts indicated.

Samples of Compositions I and V were stored in 100 ml. cylinders at 1 t0 F. and observed for phase separatron. The marked improvement in stability afforded by the inclusion of the polymers, as in Compositions I and V as compared to Composition W, is shown by Table I.

Table I Composition I V 1 Emulsion Stability Oil Water Oil Water Oil Water at 140 F.

Separation, percent 1 day slight slight 1 slight 1 slight 1 1 5 1 15 slight 3 1 9 1 37 slight 3 2 ll 1 45 30 days 7 2 '15 1 40 days 9 2 l8 1 Composition W: [water-in-oil emulsion comprising 40% plus 60% mineral oil composition containing 2% sorbitan diisobutylphenoxy (ethoxy); ethanol 7 plus 0.2% 2,6-di-tertiary-4-methyl phenol plus 0.1% phenyl alpha naphthylamine] monooleate plus 1% and (2) from about 0.5% to about 3% of an oil-soluble alkyl 'phenoxy polyalkylene glycol having theformula R-phenyl(OR) OR"OI-l where R is an alkyl radical having 4m 20 carbon atoms; and R and R" are alkylene' groups having 2 to 3 carbon atoms; and n is an integer of from 2 to 6.

2. A water-in-oil emulsion lubricant and hydraulic fluid which is from about 20% to about 45% water phase consisting essentially of water and from about 0.01% to about 2% of a water-soluble alkali metal polyacrylate having a molecular weight in the range from 25,000 to 300,000, and from about 55% to about oil phase, the oil phase being essentially a 80-100 V.I. mineral oil having a viscosity in the range from 75 to 400 SUS at F. containing (1) from about 1.5% to about 3% of a monoester of a fatty acid from 12 to 18 carbon atoms and an inner ether of an aliphatic hexahydric alcohol having 1-2 ether and 4-6 hydoxyl group and (2) from about 1% to about 2% of an oil-soluble C alkyl phenoxy(ethoxy) ethanol.

3. The composition of claim 2 containing in the emulsion from 0.01% to 2% of an oil-soluble antioxidant selected from the group consisting of alkyl phenols, phenyl-alpha-naphthylamine, and mixtures thereof, said alkyl phenols having 2 to 3 alkyl groups having from 1 to 5 carbon atoms.

4. A water-in-oil emulsionlubricant and hydraulic fluid which is from about 20% to about 45 water phase consisting essentially of Water and from about 0.01% to about 2% of a water-soluble alkali metal polyacrylatepolyacrylamide having a molecular weight in the range I from 25,000 to 300,000, and from about 55% to about 80% oil phase, the oil phase being essentially a 80-100 V1. mineral oil having a viscosity in the range from 75 to 400 SUS at 100 F. containing 1) from about 1.5% to about 3% of a monoester of a fatty acid havingfrom 12 to 18 carbon atoms and an inner ether of an aliphatic he-X-ahydric alcohol having 1-2 ether and 4-6 hydroxyl groups and (2) from about 1% to about 2% of an oilsoluble C alkyl phenoxy(ethoxy) ethanol.

5. The composition of claim 4 containing in the emulsion from 0.01% to 2% of an oil-soluble antioxidant selected from the group consisting of alkyl phenols, phenyl-alpha-naphthylamine, and mixtures thereof, said alkyl phenols having 2 to 3 alkyl groups having from 1 to 5 carbon atoms.

.(ethoxy Methanol.

-6.-A -water-in-oil emulsion lubricant and hydraulic fluid which is fromabout 120% to about 45% water phase consisting. essentially of water and from about'0.0l% to about 2% of a water-soluble alkali metal polyacrylatepolyacrylicvacid having a molecular weight in the range from 25,000 to 300,000, andfrom about 55% to about 80% oil phase, the oil phase beingtessentially a 80- 100 V.I. mineral oilhaving a viscosity in the range from 75 I to 400 SUS at 100% F. containing (1) from about 1.5% to about 3% of a monoester of a-fatty acid having from 12 to 18 carbonatoms and an inner ether of an aliphatic hexahydric alcohol having 1-2 ether and4-6 hydroxyl groups and (2)"from about 1% to about 2% of an oilsolubleCg alkyl phenoxy(ethoxy)Methanol.

7. A water-in-oil emulsion lubricant and hydraulic, b

fluid which is from about 20% to about water phase consisting essentially of :water and from, about 0. 02%*to' about 1% of a water-soluble sodium polyacrylate-polyaorylamide having a molecular weight in the range from 25,000 to 300,000, and from about to about 80% oil phase, ;the oil phase being essentially a 80-100. V.I.

mineral lubricating oil having a viscosity in the range from to 400 SUS at 100, F; containing from. about 1.5% to about 3 of a sorbitan monooleate and from about 1% to about 2% of C alkyl substituted mixture of phenoxy- 8. A water-in-oil emulsion lubricant and hydraulic fluid which is fromvabout 20% toabout 45% water phase consisting essentially of water and from about 0.02% to about 1% of' a water-soluble sodium polyacrylate-polyacrylic acid having a molecular weight in the range .from,25,000 to 300,000, and from about-55% to about oil phase, the oil phase being essentially a 80-100 V.-I.imineralllubricating oil having a viscosity in the, range from 75 to 400 SUS at Rcontaining from about 1.5% to about 3% Ma sorbitan monooleate, and

I from about 1% to about;2% of a C alkyl substituted mixture of phenom (ethoXy)Methanol.

9. The composition of'claim 8 containing in the emulsion from about 0.01% to about. 11% each. of 2,6- ditert.b-utyl-4-methylphenol, phenyl-alpha-naphthylamine and zinc diamyldithiocarbamate.

10. A water-inaoil emulsion lubricant and hydraulic fluid which isfrom about 30% to about;40% water phase consisting essentially of water and froinabout 0.02% to about 1% of a water-soluble sodium polyacrylate-polyamide having a molecular weight in the; range from 25,000 to, 300,000, and from'about 70% to about 60% oil phase, the oil phase being essentially a ,80100*V.-I.' mineral lubricatingoil having a viscosity in the range from 75 to 400SUS at 100, Fpcontainingfrorn about 1.5% to 7 about 3% of sorbitanmonooleate, and from about.1% to about 2%, of anroil soluble diisobutylphenoxy(ethoxy) ALBERT T. MEYERS, Primary Examiner.

JOSEPH H. LIBERMAN, JULIUS GREENWALD,

' I Examiners.

Claims

1. A WATER-IN-OIL EMULSION LUBRICANT AND HYDRAULIC FLUID WHICH IS FROM ABOUT 20% TO ABOUT 45% WATER PHASE CONSITING ESSENTIALLY OF WATER AND FROM ABOUT 0.04% TO ABOUT 2% OF A WATER-SOLUBLE POLYMERIC COMPOUND HAVING A MOLECULAR WEIGHT IN THE RANGE FROM 1,000 TO 500,000 AND HAVING THE FORMULA