US3640858A

US3640858A - Dual purpose lubricating compositions

Info

Publication number: US3640858A
Application number: US775917A
Authority: US
Inventors: Stephen J Harr
Original assignee: Texaco Inc
Current assignee: Texaco Inc
Priority date: 1968-11-14
Filing date: 1968-11-14
Publication date: 1972-02-08
Anticipated expiration: 1989-02-08

Abstract

This invention concerns dual-purpose packing compositions compatible with synthetic and natural lubricating oils comprising from about 30 to 50 parts by weight of a microcrystalline wax having a melting point about 50*-75* C. admixed with about 70 to 50 parts by weight of an aliphatic ester component derived from the esterification of aliphatic alcohols, diols and polyols or their ethers by aliphatic mono- or dicarboxylic acids. The packing compositions can contain from about 0.5 to 5 parts by weight of one or more extreme pressure or load bearing additives.

Description

O United States Patent [151 3,640,858 Harr 1 1 Feb. 8, 1972 [54] DUAL PURPOSE LUBRICATING 3,206,405 9/1965 Hepplewhite et a1. ..252/56 S COMPOSITIONS 3,242,075 3/1966 Hunter ..252/59 3,252,909 5/1966 Jenks ....252/56 S [72] Inventor: Stephen J. Han, Fishklll, N.Y. 3,468,701 9/ 1969 Hughes ..252/56 S [73] Assignee: Texaco Inc., New York, N.Y. FOREIGN PATENTS OR APPLICATIONS [22] 1968 749,391 5/1956 Great Britain ..252/56 s [21] Appl. No.: 775,917

Primary Examiner-Daniel E. Wyman Assistant Examiner-l. Vaughn [52] US. CL ..252/49.8, 252/56 D, 252/56 S, A"0mey K Kavanagh and Thomas whaley 252/59 [51] Int. Cl. ..Cm 7/44 57 ABSTRACT [58] Field of Search ..252/56 S, 59, 56 D, 49.8 I

This invention concerns dual-purpose packing compositions [56] References Cited co npatible with synthetic and natural lubricating oils comprising from about to parts by weight of a microcrystal- UNITED STATES PATENTS line wax having a melting point about 5075 C. admixed with about to 50 parts by weight of an aliphatic ester component 2,350,571 6/1944 Schrihng CI 3.1. derived from the esterification of aliphatic alcohols, dials and 2,729,665 1/ 1956 Buckmann polyols or their ethers by aliphatic monoor dicarboxylic 2,782,166 2/1957 Kolfenbach 61 al ..252/56 S acids The packing compositions can contain f about 05 2,922,762 1/ 1960 Morway ..252/39 to 5 parts by weight of one or more extreme pressure or load 2,944,973 7/1960 Langer et al. 252/56 S bearing additives 3,105,400 10/1963 Goppelt ..252/56 S 3,115,422 12/1963 Thomson ..252/56 S 12 Claims, No Drawings DUAL PURPOSE LUBRICATING'COMPOSITIONS This invention concerns compositions useful for packing and lubricating of turbine engine parts both during assembly and initial operation.

More particularly, this invention relates to dual-purpose packing compositions compatible with synthetic and naturally derived lubricating oils and which are capable of lubricating turbine engines under initial startup and breaking-in operating conditions.

Presently, thickened petroleum based jellies or thickened oils are employed to temporarily hold turbine engine parts during assembly. These jellies and oils are troublesome to remove and are left on parts such as bearings or rollers with the expectation that they will merge with the lubricating oils during initial operation. Unfortunately, particularly in the case of jet-type turbine engines where synthetic lubricating oils are employed, the petroleum-based packing compounds do not readily mix with the synthetic oils at startup temperatures which are below those achieved during engine warmup. Inasmuch as the normal engine lubricant is blocked from reaching critical parts during the time that elapses between engine startup and engine warmup and inasmuch as the petroleum-based packing compound does not satisfactorily lubricate these parts, adequate lubrication is not achieved. This lag in lubrication has resulted in premature failure of movable parts such as bearings and rollers. In view of the inadequacies of presently available petroleum based packing compositions, there is a need for improved packing compositions which can be used in the assembly of turbine engine parts and provide for their adequate lubrication immediately upon startup and during initial operation.

ideally, a dual purpose material is needed. The packing compound not only would have a sufficiently high viscosity to hold the engine parts during assembly but the composition must quickly and completely merge on contact with turbine lubricating oils even at relatively low temperatures. This type of material would fill a real need in the art.

It is an object of this invention, among others, to provide a dual-purpose packing composition which can be applied during the assembly of turbine engines and which will lubricate during the initial stages of engine operation. A more specific object of this invention is the development of packing compositions which dissolve even at relatively low temperatures upon contact with synthetic lubricating oils and merge to form homogenous and stable lubricants.

A further object is the preparation of the above packing compositions which in conjunction with synthetic lubricating oils provide satisfactory lubrication of the engine during the critical period of engine start-up to engine warmup during the run-in period which follows assembly and/or overhaul.

Additional objects will suggest themselves to the reader after a perusal of this invention.

The above objects are achieved by the formulation of a packing composition having two essential components present in the proportions indicated:

a. From about 30 to 50 parts by weight of a petrolatum-type material admixed with,

b. From about 70 to 50 parts by weight of an aliphatic ester component derived from the esterification of aliphatic alcohols, diols, polyols and their ethers, by aliphatic monoor dicarboxylic acids.

While the above formulation represents a satisfactory dualpurpose packing composition and a distinct improvement over the art, as is frequently the case, certain combinations of specific ingredients provide improved results and are less costly than the general class and are therefore preferred. In this instance, admixtures of petrolatum with an ester component (defined more fully below), and extreme pressure (E.P.) additives represent the preferred packing compositions of this invention. These preferred compositions compose an admixture of the following components in the proportions indicated:

a. From about 35 to 45 parts by weight of petrolat b. From about 64 to 43 parts by weight of an ester component selected from the group consisting of (l) the esters formed from dicarboxylic acids and aliphatic alcohols having one to eight carbon atoms and (2) the esters formed from monocarboxylic acids having from four to 12 carbon atoms and tetrols, and c. From about 0.5 to 5 parts by weight of one or more extreme pressure or load bearing additives.

If, in addition to lubrication, ancillary properties are sought in the packing composition the usual additives may be incorporated into the composition to replace up to a total of 5 parts by weight of either the petrolatum and/or ester component. These additives include the usual commercially available materials such as the following:

Oxidation and corrosion inhibitors such as penothiazine, orthothiazine, metathiazine, parathiazine, aromatic amines such as dioctyldiphenylamine phenyll-napthylamine, phenyllnapthylamine, quinizarin, alizarin, 1,4-dihydroxyanthraquinone and sebacic acid. Other illustrative additives are viscosity and pour depressants such as the copolymers of two or more aliphatic esters of methacrylic acid having a molecular weight between 5,000 and 20,000 surfactants of the water-resistant type such as the quaternary ammonium salts of fatty acids, polygylcol ethers, metal alkyl sulfates and sulfonates may also be employed. Additional classes of additives as well as listings of specific additives may be found in the technical and patent literature.

In order that a better understanding of the invention be obtained the following detailed description of the packing composition components and a process for preparing them is submitted.

A. Petrolatum-type material This is the generic term used throughout this application to describe those highly branched solid hydrocarbon mixtures derived from petroleum refining and which are in the form of microcrystalline waxes having a melting point about 50-75 C. (l22-l67 F). The major requirement of this material is that when admixed with the ester component in the specified proportions it produces a packing composition meeting two requirements:

a. Compatibility with lubricating oils at temperatures below those produced after engine wannup.

b. That the resultant composition have a worked penetration of between 300-400 when measured using the ASTM D 217 60 stroke worked penetration procedure.

B. Ester component This term as used throughout this application refers to the aliphatic esters derived from esterifying aliphatic alcohols, diols, polyols and their ethers with monoand/or dicarboxylic acids. The ester components are all known compounds and can be purchased as articles of commerce or prepared by conventional esterification techniques well known in the art. The aliphatic acids ordinarily contain from three to 25 carbon atoms, preferably four to 12 carbon atoms. The alcohol reactant ordinarily has from two to 20 carbon atoms preferably from four to 12 carbon atoms while the polyol or diol can have from three to 20 carbon atoms, preferably from four to 12 carbon atoms. Illustrative esters are as follows: di-isooctyl azelate, di-Z-ethylhexyl sebacate, di-Z-ethylhexyl azelate, di-2- ethyl hexyladipate, dilauryl azelate, di-sec-amyl sebacate, di- 2-(2' butoxyethoxy) ethyl alkenylsuccinate, the di-ndecanoate of 1,4-butanediol, the dilaurate of 1,4-hexanediol,

dioctanoate of l,5-pentanediol, the dilaurate of tetraethylene.

glycol, the dioctanoate of pentaethylene glycol, the trimethyol propane triheptanoate, the trimethyol propane trioctanoate, the trimethyol propane tripelargonate, pentaerythritol tetravalerate, pentaerythritol pelargonate, pentaerythritol butyrate, pentaerythritol caprylate, pentaerythritol heptanoate, pentaerythritol octanoate, pentaerythritol caprylate. Mixtures of one or more of these esters including small quantities of the free acids can also be used. The preferred esters are selected from the group consisting of:

a. Esters formed by the reaction of sebacic acid with aliphatic alcohols having from four to 12 carbon atoms and their mixtures.

b. Esters formed by the reaction of aliphatic acids with pentaerythritol, wherein the aliphatic acid contains from four to 12 carbon atoms.

C. Extreme Pressure Additives As disclosed earlier, the preferred E. P. additive is tricresyl phosphate in concentrations of 0.5 to 3 percent by weight. However, satisfactory results are obtained where the same concentrations of other E. P. additives are employed. These additives are generally organic compounds containing phosphorous and sulfur such as the esters of phosphorous acids, organic phosphates and phosphites such as zinc dithiophosphate, neutral aromatic sulfur compounds, selenides, sulfurized long-chain olefins, phosphorous acid esters having sulfurized radicals and heavy metal soaps such as lead naphthenate.

D. Process For Preparing Packing Compositions The process employed to prepare the packing compositions is simple to perform and requires no particular equipment or precautions. The petrolatum-type component and ester component are combined with any optional additives including E. P. additives. No particular order of addition is needed and standard laboratory or plant mixing or blending equipment will suffice. The combined components and optional additives are stirred or agitated while heating between about 175 to 250 F. until a homogenous mixture is produced. Ordinarily this requires only a matter of minutes with to 15 minutes being typical. Longer stirring and heating times are not detrimental. After a homogenous mixture is obtained the source of heat and agitation are removed and the mixture is poured into the desired container and allowed to set. A period of several hours is usually sufficient with 3 to 12 hours representing an average setting and cooling time depending upon the quantity of compound in the container. Upon setting, the packing composition has a consistency resembling that of No. 1 grade grease (300375,ASTM D217 60 stroke worked penetration) and is sufficiently tacky to hold the turbine parts during assembly.

The following examples describe the preparation of dualpurpose packing compositions and their evaluation.

EXAMPLE 1 Penetration ASTM-D-Z l 7 unworkcd 287 60 strokes 422 Dropping Point ASTM-D-S66-18 132 ck. 134

The material dissolves upon contact with a sebacate ester synthetic lubricating oil (SATO 5180) at 68 F. but is too soft for holding the turbine parts during assembly. A packing composition comprising 100 percent by weight of the same petrolatum, stirred, heated and set under the same conditions was hard enough to hold parts during assembly but did not dissolve upon contact with the same synthetic lubricating oil at the same temperature.

EXAMPLE 2 A 30 parts by weight portion of the same petrolatum used in Example 1 is blended with 70 parts by weight of the ester of Example 1 and the mixture heated to 200-250 F. with stirring for 5 minutes. At the end of this time the heating and stirring is terminated and the mixture allowed to cool at the ambient temperature for 2 hours. The packing material had the following properties.

Dropping Point Penetration ASTM-D-566-l8 ASTMD217 unworked 60 strokes EXAMPLE 3 in this example, the same heating, stirring and cooling procedure used in Examples 1 and 2 is followed to prepare a mixture comprising 35 parts by weight of the petrolatum of Examples 1 and 2 and 65 parts by weight of the following esters of pentaerythritol.

38% by weight valerate 13% by weight 2-methyl-pentanoate 32% by weight octanoate 17% by weight of pelargonate The consistency of the product is comparable to a No. 1 grade grease and the product had a penetration value of 310-340 using ASTM-D-217 60 stroke worked penetration procedure.

EXAMPLE 4 In this example the same mixing, heating, stirring and setting procedure as well as the same quantities of components used in Example 3 are employed. While the same petrolatum is used, the mixture of pentaerythritol esters is replaced on a weight by weight basis by the sebacate ester of Examples 1 and 2. After setting the packing composition had a consistency comparable to No. 1 grade grease and had a 60 stroke worked penetration value of 310-340 (ASTM-D-2l7 procedure).

The packing composition dissolves on contact with the synthetic lubricating oil used in Example 2 and exhibits good holding power during assembly.

EXAMPLE 5 Three packing formulations are prepared using the same quantities of petrolatum and ester component as described in Example 4. Heating is at 200250 F. with stirring for 5 minutes and the mixture is cooled for 4 hours. After setting the compositions had comparable consistency and penetration values to those obtained in Examples 3 and 4. All three compositions dissolved upon contact with the same synthetic lubricating oil described previously and all are satisfactory for the assembly of turbine engine parts. The compositions are as follows:

Formulation 1 Formulation 2 35% by weight of a wax melting at -132F. 35% by weight ofa wax containing 2% by weight polyethylene melting at 122-124 65% by weight of trimethylol propane triheptanoate 65% by weight of pentaerythritol esterified with a mixture of 1% by weight butyric acid, 92% by weight valeric acid. 4% caprylic acid, 1% by weight of pelargonic acid and 20% by weight capric acid. The ester mixture had the following vlscosity.

C.S. at 40 F- 34.38 C.S. at 210 F 380 CS. at 100 F- 17.62

Formulation 3 35% by weight ofa wax melting at F. 65% by weight of trimethylol propane esterified with a monobasic acid mixture consisting of 2% by weight values, 9% by weight capric, 13% by weight hcptanoic, 7% by weight branched chain cctanoic, 65% by weight pelargonic acid and 1% by weight capric acids. The material had the following viscosities.

G5. at 210 F.4.29

C.S. at 100 F.l9.98

G8. at 40 F.36.38

EXAMPLE 6 A 35 parts by weight portion of petrolatum described in Examples l to 3 is combined with 62 parts by weight of the pentaerythritol ester mixture of Example 2 and 3 parts by weight of tricresyl phosphate E.P. additive. After mixing the material is heated to 200-250 F. with stirring for 5 minutes. At the end of that time the packing mixture is allowed to cool without stirring for 4 hours. The resultant product is comparable in all respects to that obtained in Example 3 except that it has increased extreme pressure capabilities.

EXAMPLE 7 Each of the formulations prepared in Examples 1 to 6 are evaluated as follows:

A Timken No. 09074 Tapered Roller Bearing is packed in each of the exemplified packing formulations and spun for 30 seconds at 2,000 rpm. to determine the rapidity of softening and the ease of removal of the packing material. In each instance approximately 20 percent of the packing formulation splashed off and the balance became extremely soft and dropped off the bearing.

A Pratt and Whitney JT30 bearing is packed in each of the exemplified formulations and heated for 5 minutes at 120 F. The packing softened but still has sufficient consistency to hold the bearing in place indicating the suitability of the packing compositions for satisfactory performance at high ambient temperatures. Each of the packed bearings are soaked in separate containers of synthetic oils one primarily composed of di-2-ethylhexyl sebacate and the other primarily a mixture of the alkyl esters of pentaerythritol. In each instance, 60 to 70 percent of the various packing formulations dissolved after being in contact with each of the two synthetic oils after a relatively short time.

The above evaluation establishes the value of the inventive compositions for their intended purpose.

The novel dual-purpose packing compositions of this invention offer significant advantages compared to the wholly petroleum based jellies and thickened oils of the prior art. For example, the consistency of the unworked composition is sufficient to permit its use to hold parts during assembly, moreover, its compatibility with turbine lubricating oils is excellent and rapid. Complete dissolution of the packing from the parts into the turbine lubricating oil takes place upon working contact even at the relatively low temperatures encountered between engine startup and engine warmup. In addition the compositions are simple to formulate and inexpensive to prepare.

As the previous discussion and illustrative examples indicate, numerous changes and modifications in the components of the packing compositions as well as in the conditions used to formulate them can be made without departing from the inventive concept. The metes and bounds of this invention are best determined by the preceding disclosure taken in conjunction with the claims which follow.

What is claimed is:

1. A dual-purpose packing composition compatible with lubricating oils and having a consistency suitable for packing engine parts during assembly comprising an admixture of the following components in the indicated proportions:

a. From about 30 to 50 parts by weight of a microcrystalline wax having a melting point about 5075 C., and

b. From about 70 to 50 parts by weight of an aliphatic ester component derived from the esterification of aliphatic alcohols, diols, polyols and theirethers with a aliphatic acid selected from the group consisting of monoand dicarboxylic acids.

2. The composition of claim 1 wherein the alcohol has from four to 12 carbon atoms.

3. The composition of claim 1 wherein the polyol is a triol.

4. The composition of claim 3 wherein the triol is trimethyolpropane.

5. The composition of claim 1 wherein the polyol is a tetrol.

6. The composition of claim 5 wherein the tetrol is pentaerythritol.

7. The composition of claim 6 wherein the pentaerythritol ester is derived from a mixture of monocarboxylic acids having from four to 12 carbon atoms.

8. The composition of claim 2 wherein the ester is a sebacate ester.

9. A dual-purpose packing composition compatible upon contact with lubricating oils and capable of providing lubrication from the assembly of jet engines to operation comprising an admixture of the following components in the indicated proportions:

a. From 35 to 45 parts by weight of microcrystalline wax having a melting point of from to F. an ASTM D 1321 penetration value of from 30 to 1 l0 and a viscosity S.U.S. at 210 F. of 60.0-120,

b. From 64 to 43 parts by weight of an ester selected from the group consisting of the alkyl esters of sebacic acid and the fatty acid esters of pentaerythritol, wherein the alkyl groups contain from two to 10 carbon atoms and the fatty acid contain from three to 25 carbon atoms and c. From 0.5 to 5 parts by weight of an extreme pressure lubricant additive.

10. The composition of claim 9 wherein the extreme pressure lubricant is tricresyl phosphate.

11. The composition of claim 10 wherein the ester is a pentaerythritol ester prepared from fatty acids containing from four to 12 carbon atoms.

12. The composition of claim 10 wherein the ester is di-2- ethylhexyl sebacate.

Claims

2. The composition of claim 1 wherein the alcohol has from four to 12 carbon atoms.
3. The composition of claim 1 wherein the polyol is a triol.
4. The composition of claim 3 wherein the triol is trimethyolpropane.
5. The composition of claim 1 wherein the polyol is a tetrol.
6. The composition of claim 5 wherein the tetrol is pentaerythritol.
7. The composition of claim 6 wherein the pentaerythritol ester is derived from a mixture of monocarboxylic acids having from four to 12 carbon atoms.
8. The composition of claim 2 wherein the ester is a sebacate ester.
9. A dual-purpose packing composition compatible upon contact with lubricating oils and capable of providing lubrication from the assembly of jet engines to operation comprising an admixture of the following components in the indicated proportions: a. From 35 to 45 parts by weight of microcrystalline wax having a melting point of from 130* to 160* F. an ASTM D 1321 penetration value of from 30 to 110 and a viscosity S.U.S. at 210* F. of 60.0- 120, b. From 64 to 43 parts by weight of an ester selected from the group consisting of the alkyl esters of sebacic acid and the fatty acid esters of pentaerythritol, wherein the alkyl groups contain from two to 10 carbon atoms and the fatty acid contain from three to 25 carbon atoms and c. From 0.5 to 5 parts by weight of an extreme pressure lubricant additive.
10. The composition of claim 9 wherein the extreme pressure lubricant is tricresyl phosphate.
11. The composition of claim 10 wherein the ester is a pentaerythritol ester prepared from fatty acids containing from four to 12 carbon atoms.
12. The composition of claim 10 wherein the ester is di-2-ethylhexyl sebacate.