NO128947B

NO128947B -

Info

Publication number: NO128947B
Application number: NO7172A
Authority: NO
Inventors: M Nielsen
Original assignee: M Nielsen
Priority date: 1972-01-14
Filing date: 1972-01-14
Publication date: 1974-02-04
Also published as: DE2301716B2; DE2301743A1; DK133729B; DE2301743C3; DK132377B; DK133729C; DE2301743B2; DE2301716A1; SE395838B; DK132377C; SE394964B

Description

Smøremiddel. Lubricant.

Det har tidligere blitt foreslått syn-tetiske smøremidler som består av en blanding av en flytende alifatisk ester av en mettet alifatisk karbonsyre og en polyester med den generelle formel: HO(R200CR,COO)„RjOH (I) hvor Ri er en alifatisk dikarbonsyres kull-vannstoffradikal, R2 er en glykols kull-vannstoffradikal og n er et tall fra 1—10 (se britisk patent nr. 763 077). Synthetic lubricants have previously been proposed which consist of a mixture of a liquid aliphatic ester of a saturated aliphatic carboxylic acid and a polyester of the general formula: HO(R200CR,COO)„RjOH (I) where Ri is the carbon of an aliphatic dicarboxylic acid -hydrogen radical, R 2 is a glycol carbon hydrogen radical and n is a number from 1-10 (see British patent no. 763 077).

Det er funnet at det kan fremstilles spesielle blandinger av ovenstående type eller av lignende art som ovenstående type og som har egenskaper som gjør dem spesielt egnet til smøremiddel for gassturbin for fly. It has been found that special mixtures of the above type or of a similar type to the above type can be produced and which have properties which make them particularly suitable as lubricants for aircraft gas turbines.

Ifølge oppfinnelsen omfatter en smøre-middelsammensétning, en blanding av en mettet alifatisk dikarbonsyres flytende alifatiske diestere og en polyester som er løselig i diesteren og som har den generelle formel I overfor, idet: According to the invention, a lubricant composition comprises a mixture of liquid aliphatic diesters of a saturated aliphatic dicarboxylic acid and a polyester which is soluble in the diester and which has the general formula I opposite, wherein:

n er et helt tall, n is an integer,

Ri er alkylengrupper som har 4—14, Ri are alkylene groups having 4-14,

fortrinnsvis 6—10 kullstoff atomer og preferably 6-10 carbon atoms and

Ra er oksyderte kullvannstoffradlkaler med formelen Ra are oxidized coal hydrogen radkals with the formula

idet: whereas:

x er 0 eller et helt tall, y er et helt tall og x + y overstiger ikke 5, x is 0 or an integer, y is an integer and x + y does not exceed 5,

Ro er en metyl- eller etylgruppe, fortrinnsvis en metylgruppe og Ro is a methyl or ethyl group, preferably a methyl group and

R7 er en alkylgruppe som har 1—4 kullstoffatomer, fortrinnsvis en metylgruppe. De relative forhold av diester og polyester i blandingen er slik at blandingens viskositet ved 99° C er 3—30, fortrinnsvis 3—10, spesielt 6—10, centistokes. R7 is an alkyl group having 1-4 carbon atoms, preferably a methyl group. The relative proportions of diester and polyester in the mixture are such that the viscosity of the mixture at 99° C is 3-30, preferably 3-10, especially 6-10, centistokes.

Alkyl- og alkylengruppene kan være rette eller forgrenede kjeder. The alkyl and alkylene groups can be straight or branched chains.

Foretrukne diestere for bruk i blandingene ifølge oppfinnelsen er de med formel: Preferred diesters for use in the mixtures according to the invention are those with the formula:

idet Rs er en alkylengruppe som har 4—14 kullstoffatomer og R4 er alkylgrupper, fortrinnsvis forgrenede kjeder som har 4—18 kullstoffatomer. wherein R s is an alkylene group having 4-14 carbon atoms and R 4 are alkyl groups, preferably branched chains having 4-18 carbon atoms.

Eksempler på egnede diestere er: Examples of suitable diesters are:

(I) di(2-etylheksyl)sebacat; (di-oktyl sebacat), (II) di(3 : 5 : 5-trimetylheksyl) sebacat; (di-nonyl sebacat), (III) 2-etylheksyl(3 : 5 : 5-trimetylheksyl) sebacat; (oktyl-nonyl sebacat) og (IV) blandinger av (I), (II) og (III). (I) di(2-ethylhexyl)sebacate; (di-octyl sebacate), (II) di(3 : 5 : 5-trimethylhexyl) sebacate; (di-nonyl sebacate), (III) 2-ethylhexyl(3 : 5 : 5-trimethylhexyl) sebacate; (octyl-nonyl sebacate) and (IV) mixtures of (I), (II) and (III).

Foretrukne polyestere er de som ved 25° C har en viskositet på 50—20 000 centistokes, spesielt 500—10.000 centistokes, spesielt de hvori Ri har 7 eller 8 kullstoffatomer, spesielt oktametylen, 1:1: 3-tri-metyltetrametylen eller 1:3: 3-trimetyl-tetrametylen, og Ra er radikaler av formelen II hvori x + y = 1—2. Preferred polyesters are those which at 25° C. have a viscosity of 50-20,000 centistokes, especially 500-10,000 centistokes, especially those in which Ri has 7 or 8 carbon atoms, especially octamethylene, 1:1: 3-trimethyltetramethylene or 1: 3: 3-trimethyl-tetramethylene, and Ra are radicals of the formula II in which x + y = 1-2.

Det må forstås at forskjellige Ri grupper, forskjellige Ro grupper, forskjellige R7 og forskjellige verdier av x og y kan være tilstede i et hvert polyestermolekyl, at forskjellige R4 grupper kan være tilstede i hvert diestermolekyl og at blandinger av forskjellige polyestermolekyler og/eller forskjellige diestermolekyler kan være tilstede i den samme blanding. It must be understood that different Ri groups, different Ro groups, different R7 and different values of x and y can be present in each polyester molecule, that different R4 groups can be present in each diester molecule and that mixtures of different polyester molecules and/or different diester molecules may be present in the same mixture.

Polyestere til bruk i smøringsblandin-gen ifølge oppfinnelsen kan fremstilles ved Polyesters for use in the lubricating mixture according to the invention can be produced by

å bringe følgende bestanddeler til å reagere i et eller flere trinn: (a) en syre eller syrer med formelen to react the following constituents in one or more steps: (a) an acid or acids of the formula

HOOCRtCOOH, og HOOCRtCOOH, and

(b) en diol eller dioler med formelen (b) a diol or diols of the formula

idet Ri, Ro, R7, x og y har de ovenfor angitte verdier, diolens eller diolenes molekylar - deler er større enn, men fortrinnsvis ikke mere enn to ganger større enn, syren eller syrenes molekylardeler. Diolene ifølge formel III kan fremstilles ved å bringe etylenoksyd til å reagere med en diol med formelen HOCH2C(Ro)(R7)CH2OH, idet molekylarforholdet etylenoksyd til diol ikke over-skrider 5 : 1, og fortrinnsvis er 1—2 : 1. Som angitt ovenfor kan blandinger av polyestere av ovenstående formel anvendes i smøringsblandingen, dvs. polyestere som har forskjellige verdier av n og som har forskjellige syre- og diol-residuer. Med en slik blanding vil selvsagt middelverdien av n ikke nødvendigvis være et helt tall. Når en polyesterblanding skal fremstilles behøver følgelig molekylarforholdet til bestanddelene som skal bringes til å reagere ikke å foreligge i heltalls-forhold. since Ri, Ro, R7, x and y have the values stated above, the molecular parts of the diol or diols are greater than, but preferably not more than twice greater than, the molecular parts of the acid or acids. The diols according to formula III can be prepared by reacting ethylene oxide with a diol of the formula HOCH2C(Ro)(R7)CH2OH, the molecular ratio of ethylene oxide to diol not exceeding 5:1, and preferably 1-2:1. As indicated above, mixtures of polyesters of the above formula can be used in the lubrication mixture, i.e. polyesters which have different values of n and which have different acid and diol residues. With such a mixture, the mean value of n will of course not necessarily be a whole number. Consequently, when a polyester mixture is to be produced, the molecular ratio of the components to be reacted need not be in whole number ratios.

Eksempler på syrer som kan benyttes ved fremstillingen av polyestere er adipin-syre, pimelinsyre, korksyre, azelainsyre og brassylsyre. Examples of acids that can be used in the production of polyesters are adipic acid, pimelic acid, corkic acid, azelaic acid and brassylic acid.

Spesielt tilfredsstillende syrer har vist seg å være: (a) sebacinsyre, og (b) en ekvimolekylar blanding av 2:2: 4-trimetyladipin, 2:4:4-trimetyladipin og sebacinsyre. Particularly satisfactory acids have been found to be: (a) sebacic acid, and (b) an equimolecular mixture of 2:2:4-trimethyladipine, 2:4:4-trimethyladipine and sebacic acid.

Spesielt tilfredsstillende dioler ble fremstilt som følger: 416 g (4 mol) med neopentylglykol (2 : 2-di-metyl-l : 3-propandiol) ble oppvarmet til 160° C og en liten mengde sink-klorid (katalysator) ble innrørt. Deretter ble etylenoksyd ledet gjennom den varme blanding inntil 310 g (ca. 7 mol) etylenoksyd hadde forbundet seg med neopen-tylglykolet. Deretter ble trykket redusert til 1 mm kvikksølv og diolproduktet som destillerte over i temperaturområdet 60— 145° C ble samlet. Molekylvekten på diolproduktet (i det følgende kalt diol Dl) var 180 og det bestod vesentlig av en blanding av dioler av formelen II, idet x + y hadde en middelverdi på ca. 1,7. Particularly satisfactory diols were prepared as follows: 416 g (4 mol) of neopentyl glycol (2:2-dimethyl-1:3-propanediol) were heated to 160° C. and a small amount of zinc chloride (catalyst) was stirred in. Ethylene oxide was then passed through the hot mixture until 310 g (about 7 moles) of ethylene oxide had combined with the neopentyl glycol. The pressure was then reduced to 1 mm of mercury and the diol product which distilled over in the temperature range 60-145° C was collected. The molecular weight of the diol product (hereinafter called diol D1) was 180 and it essentially consisted of a mixture of diols of the formula II, x + y having a mean value of approx. 1.7.

Noe av diol Dl ble ytterligere destillert inntil det ble oppnådd et diolprodukt (i det følgende kalt diol D2) som hadde følgende egenskaper: Some of the diol D1 was further distilled until a diol product (hereinafter called diol D2) was obtained which had the following properties:

Kokepunkt: 132,7° C ved 9,5 mm Hg Boiling point: 132.7° C at 9.5 mm Hg

n ^ : 1.4482 n ^ : 1.4482

Analyse: C, 56,75 %; H, 10,7%. Assay: C, 56.75%; H, 10.7%.

Disse egenskaper tilsvarer en formel C7H10O3, dvs. en forbindelse med formel III hvori Ro og R7 begge er metylgrupper, x = 0 og y = 1. These properties correspond to a formula C7H10O3, i.e. a compound of formula III in which Ro and R7 are both methyl groups, x = 0 and y = 1.

Blandingen ifølge oppfinnelsen inneholder fortrinnsvis 5—60 vektspst. polyester, spesielt 5—35 %, og resten av blandingen er vesentlig diester. The mixture according to the invention preferably contains 5-60 wt. polyester, especially 5-35%, and the rest of the mixture is essentially diester.

Hvis ønsket kan noe antioksydant for smøremidlet, f. eks. fenotiazin, blandes i blandingen. If desired, some antioxidant for the lubricant, e.g. phenothiazine, is mixed into the mixture.

Eksempelvis ble polyestere P121, P122 og P131 fremstilt av bestanddelene oppstilt i tabell 1 etter følgende fremgangsmåte: Bestanddelene ble brakt til å reagere i en tre-halset 500 ml kolbe utstyrt med et røreverk, et innledningsrør for kvelstoff og en vertikal dampoppvarmet kondensator forbundet med en vannavkjølet nedad-gående kondensator. Kvelstoff ble ledet gjennom i en mengde på ca. 5 1 pr. time og følgende oppvarmningssyklus utført. For example, polyesters P121, P122 and P131 were prepared from the components listed in Table 1 according to the following procedure: The components were reacted in a three-necked 500 ml flask equipped with a stirrer, a nitrogen inlet tube and a vertical steam-heated condenser connected to a water-cooled downdraft condenser. Nitrogen was passed through in an amount of approx. 5 1 per hour and the following heating cycle performed.

Kolbens innhold ble hurtig oppvarmet til 130° C (alle temperaturer måles inn-vendig) hvor det holdes i fire timer. Etter at reaksjonen var blitt fortsatt i 2 timer ved hver av temperaturene 150° C, 180° C og 200° C ble destillatet samlet. Diolinn-holdet ble beregnet av en bestemmelse av refraksjonsindeksen og etter at denne mengde hadde blitt tilsatt til kolben ble oppvarmingen utført ved 240° C inntil syretallet falt under 5 mg KOH/g. Ved dette trin ble trykket redusert til 17 mm kvikk-sølv og reaksjonen ble fortsatt ved 240° C til syretallet falt under 1 mg KOH/g. The contents of the flask were quickly heated to 130° C (all temperatures are measured internally) where it was held for four hours. After the reaction had been continued for 2 hours at each of the temperatures 150° C., 180° C. and 200° C., the distillate was collected. The diolin content was calculated from a determination of the refractive index and after this amount had been added to the flask, the heating was carried out at 240° C. until the acid number fell below 5 mg KOH/g. At this step the pressure was reduced to 17 mm Hg and the reaction was continued at 240° C. until the acid number fell below 1 mg KOH/g.

Tabell 1 angir sammensetningen og egenskapene til polyestrene P121, P122 og P131. Table 1 indicates the composition and properties of the polyesters P121, P122 and P131.

En ekvimolær blanding av 2 : 2 : 4-tri-metyl-adipin, 2:4: 4-trimetyladipin og sebasinsyre. An equimolar mixture of 2:2:4-trimethyladipine, 2:4:4-trimethyladipine and sebacic acid.

Polyestrene P121, P122 og P131 ble blandet med en diester og fenotiazin for å danne blandingene B121, B122 og B131, som har sammensetningene og egenskapene vist i tabell II. For sammenligning er også noen egenskaper angitt for en han-delsmessig tilgjengelig syntetisk smørning for gassturbin for fly, nemlig blanding (X) og for en blanding (B61) som inneholder en kjent polyester med formel I (P61) som vesentlig består av et poly-(propylen-sebacat) som finnes i handelen under vare-merket «Reoplex 100». Diesteren ble fremstilt av ekvimolekylare mengder med sebacinsyre, 2-etylheksanol og 3:5: 5-tri-metylheksanol. I tillegg til oktyl-nonylsebacat inneholdt produktet også di-oktyl-og di-nonylsebacat. Polyesters P121, P122 and P131 were blended with a diester and phenothiazine to form blends B121, B122 and B131, which have the compositions and properties shown in Table II. For comparison, some properties are also indicated for a commercially available synthetic aircraft gas turbine lubricant, namely blend (X) and for a blend (B61) containing a known polyester of formula I (P61) which essentially consists of a poly- (propylene sebacate) which is available in the trade under the brand name "Reoplex 100". The diester was prepared from equimolar amounts of sebacic acid, 2-ethylhexanol and 3:5:5-trimethylhexanol. In addition to octyl nonyl sebacate, the product also contained di-octyl and di-nonyl sebacate.

Det vil ses at blandingene ifølge oppfinnelsen (blandingene B121, B122 og B131) har bedre termiske stabilitetsegenskaper enn blandingen B61. It will be seen that the mixtures according to the invention (mixtures B121, B122 and B131) have better thermal stability properties than mixture B61.

(God termisk stabilitet angis ved en liten viskositetsforandring etter høytempe-raturbehandlingen. En viskositetsforøkelse ved 38° C etter høytemperaturbehandlin-gen foretrekkes fremfor en forminskelse). Videre har blandingene B121, B122 og B131 utmerkede lavtemperaturegenskaper, mens blanding B61 gir en dårlig ytelse ved lave temperaturer på tross av det faktum at den inneholder en større del av den mindre viskøse diester-bestanddelen enn blandingene B121 og B131. Blanding X har også dårlige lavtemperaturegenskaper. (Good thermal stability is indicated by a small change in viscosity after the high-temperature treatment. An increase in viscosity at 38° C after the high-temperature treatment is preferred to a decrease). Furthermore, blends B121, B122 and B131 have excellent low temperature properties, while blend B61 gives poor low temperature performance despite the fact that it contains a greater proportion of the less viscous diester component than blends B121 and B131. Mixture X also has poor low-temperature properties.

Lav-temperaturegenskapene til blandingene ifølge oppfinnelsen kan hvis ønsket bli ytterligere forbedret ved tilsetnin-gen av en krystallisasjonshindrer, dvs. en polymerisert alkylester av akryl- eller metakrylsyre, men det er en fordel hvis gode lav-temperaturegenskaper kan opp-nås uten tilsetning av slike materialer, da det har en motsatt virkning både på den termiske stabilitet og skjærestabiliteten til blandinger, hvori de inneholdes. The low-temperature properties of the mixtures according to the invention can, if desired, be further improved by the addition of a crystallization inhibitor, i.e. a polymerized alkyl ester of acrylic or methacrylic acid, but it is an advantage if good low-temperature properties can be achieved without the addition of such materials, as it has an opposite effect both on the thermal stability and the shear stability of mixtures in which they are contained.

Den åpent beger-prøven som det refe-reres til i tabell II ble utført på følgende måte. 250 ml olje ble oppvarmet i et 400 The open beaker test referred to in Table II was carried out in the following manner. 250 ml of oil was heated in a 400

ml beger i en ovn som ble holdt ved en lufttemperatur på 300° C. Etter oppvarming i 2, 3, 4 og 5 timer ble det tatt ut prøver av oljen og viskositeten ble målt ved 38° C. ml beaker in an oven maintained at an air temperature of 300° C. After heating for 2, 3, 4 and 5 hours, samples of the oil were taken and the viscosity was measured at 38° C.

Claims

1. Lubricant, characterized by a mixture of a saturated aliphatic dicarbon-

acid liquid aliphatic diesters and a polyester which is soluble in the diesters and which has the general formula idet n is an integer, R 1 are alkylene groups having 4-14, carbon atoms and R- 2 are oxygenated carbon hydrogen radicals with the formula where: x is 0 or an integer, y is an integer and x + y does not exceed 5, Ro is a methyl or ethyl group and R7 is an alkyl group having 1-4 carbon atoms, the relative ratio between diesters and polyesters in the mixture is such that the viscosity of the mixture at 99° C is 3-30 centistokes.

2. Lubricant according to claim 1, characterized in that the relative ratio between diester and polyester in the mixture is such that the viscosity of the mixture at 99° C is 3-10, preferably 6-10, centistokes.

3. Lubricant according to claim 1 or 2, characterized in that the mixture contains 5-60, preferably 5-35 wt. polyester.

4. Lubricant according to any one of the preceding claims, characterized in that the dieter has the formula wherein Rs is an alkylene group having 4-14 carbon atoms and R4 is alkyl groups having 4-18 carbon atoms.

5. Lubricant according to claim 4, characterized in that R4 has a branched chain.

6. Lubricant according to claim 5, characterized in that the diester is a mixture of di(2-ethylhexyl)-sebacate, di(3:5:5-trimethylhexyl)-sebacate and 2-ethylhexyl-(3:5:5- trimethylhexyl)-sebacate.

7. Lubricant according to any one of the preceding claims, characterized in that the polyester is one in which Rc are methyl groups.

8. Lubricant according to any one of the preceding claims, characterized in that the polyester is one in which R7 are methyl groups.

9. Lubricant according to any one of the preceding claims, characterized in that the polyester is one in which Ri are alkylene groups having 6-10 carbon atoms.

10. Lubricant according to any one of the preceding claims, characterized in that the polyester at a temperature of 25° C has a viscosity of 50-20,000, preferably 500-10,000 centistokes.

11. Lubricant according to claim 9 or 10, characterized in that the polyester is one in which Ri has 7 or 8 carbon atoms.

12. Lubricant according to claim 11, characterized in that the polyester is one in which Ri is one or more of the following radicals: octamethylene, 1:1:3-trimethyltetramethylene or 1:3:3-trimethylethylene tramethylene.

13. Lubricant according to any one of the preceding claims, characterized in that x -\- y = 1-2.

14. Lubricant according to any one of the preceding claims, characterized by an additional content of antioxidant for lubricants, preferably phenothiazine.

15. Lubricant according to claim 1, characterized in that the polyester has been produced by reacting in one or more steps (a) an acid or acids with <1> the formula HOOCRiCOOH and (b) a diol or diols with the formula wherein Ri, Ro, R7, x and y have the values stated in claim 1, and the molecular ratio of the diol or the diols is greater than the molecular ratio of the acid or acids.

16. Lubricant according to claim 15, ka- characterized in that the molecular ratio of the diol or the diols is not more than twice the molecular ratio of the acid or the acids.

17. Lubricant according to claim 15 or 16, characterized in that the diol of formula III is prepared by reacting ethylene oxide with a diol of the formula HOCH2C(Rc,)(R7)-CH2OH, the molecular ratio between ethylene oxide and diol not exceeding 5 :1.

18. Lubricant according to claim 17, characterized in that the molecular ratio between ethylene oxide and diol is 1-2:1.

19. Lubricant according to one of claims 15-18, characterized in that the acid is sebacic acid or an equimolecular mixture of 2:2:4-trimethyladipine, 2:4:4-trimethyl-adipine and sebacic acids.