DE935923C - Lubricating greases - Google Patents

Description

Issued on the basis of the First Overhead Line Act of July 8, 1949

(WiGBl. P. 175)

FEDERAL REPUBLIC OF GERMANY

ISSUED JANUARY 5, 1956

GERMAN PATENT OFFICE

PATENT LETTERING

CLASS 23c GROUP 1 04

St 422 g IVd j 23 c

The inventors have requested not to be named

Standard Oil Development Company, Elizabeth, N.J. (V. St. A.)

Lubricating greases

Patented in the territory of the Federal Republic of Germany on December 18, 1951

Patent application published on June 8, 1955 Patent granted published on November 3, 1955

The · priority of registrations in the V. St. v. America December 22nd to December 30th, 1950 and May 18, 1951 is used

The invention relates to new lubricating greases by

Thickening of lubricant bases by means of N-acylaminophenols are produced and optionally also small amounts of the known soap thickeners may contain.

It has been found that lubricating greases, e.g. B. those that are used to lubricate the coil ring in suitable for spinning without the use of ordinary fat-forming soaps or only with a very small amount ίο Addition of them can be made by using the lubricating oils, ζ. Β. Synthetic-based lubricating oils, hereinafter referred to as "synthetic lubricating oils", Mineral fats and resin extracts from mineral oils thickened with one or more N-acyl-aminophenols. For this purpose, it is expedient to use p-aminophenols or their nucleus-substituted alkyl derivatives, whose acyl group contains 12 to 22 carbon atoms.

These N-acyl-aminophenols and their nucleus-substituted ones Derivatives can be represented by the formula:

HO

COR

Here, R represents an alkyl group of 12 to 22 carbon atoms and R ₁ and R _{2 represent} hydrogen atoms or

identical or dissimilar alkyl groups, their each contains up to 20, expediently 4 to 15, carbon atoms The acyl-amino group can be in the o-, m- or p-position to the hydroxyl group; compounds are preferred with m and p configurations. - - '

N-acyl-aminophenols are preferably used with p-position acyl-amino group, the acyl group of which contains 16 to 22 carbon atoms. Examples are: N-palmitoyl-p-aminophenol, N-stearoyl-p-aminophenol and N-arachidoyl-p-aminophenol, with N-stearoyl-p-aminophenol is preferred.

It can also have the composition given above corresponding alkylated compounds can be used. Examples of such Compounds are: N-n-Valeryl ^ -amino ^ -pentadecyl-phenol, N-n-propanoyl ^ -amino-s-pentadecylphenol, N-n-pentanoyl-4-amino, 2,6-di-tertiary butylphenol and N-n-hexoyl ^ -amino ^ -hexylphenol.

As a basis one generally uses the oil which would be suitable for the respective purpose if a liquid could be used in place of the fat. Examples thereof are primary mineral lubricating oils whose viscosity at 37.8 ⁰ C between 600 and 1000 SUS Hegt. Such oils can be paraffinic or naphthenic in nature and cleaned by means of the. known processes.

For special purposes, such as. B. the production of lubricating greases for coil rings in the Spinning, you can use bleached mineral fat as a basis.

Another example of lubricants which can be thickened by adding the compounds identified above are those recently developed Silicone oils. Typical representatives of such silicone oils are the polymers of methylphenyl-silicon, ethyl, butyl-silicon, methyl-cyclo-hexyl-silicon, di-cyclohexyl-silicon, Di-phenyl-silicon, phenyl-ethyl-silicon, Phenyl-propyl-silicon.

Fats have already been made by mixing such polymeric silicone oils with the typical Soap thickeners thickened to a kind of fat, for which lithium stearate was preferably used. Meanwhile These common fat-forming soaps, such as the lithium stearate just mentioned, cannot dispersed directly, but only under pressure, with the silicone oils in order to have a fat-forming effect.

It has been found that such polymeric silicone oils when using the acyl-p-aminophenols Let it thicken to a fat consistency by simply heating. The fats produced in this way have on the one hand all of the advantageous properties inherent in polymeric silicone oils and contain on the other hand none of the soap residues that were inevitable until then. You can do any of the above Use acyl-p-aminophenols; stearoyl-p-aminophenol is preferably used.

Further examples of lubricants, which according to the invention by thickening with the inventive N-acyl-aminophenols assume greasy consistency, the lubricants are based on the Diesters of dicarboxylic acids, polyethers and complex linear esters obtained by esterification of dibasic acids "or glycolic monomers Acids and alcohols can be obtained! However, due to the solubility of the phenolic compounds The usual fat-forming soaps cannot be completely dispensed with in the lubricant, however the desired fat consistency is achieved by using the phenolic compounds ■ as a thickening agent even with much smaller amounts of fat-forming soaps.

It is known to produce lubricating greases from such esters. However, this procedure is difficult and makes the use of large amounts of soap, on the order of 12 to 21 percent by weight necessary. In addition, it is usually necessary to add 0.5 to 5 percent by weight of stabilizer, z. B. the compound of an amphoteric metal, such as zinc, or aluminum, for example an oxide, Carbonate or a soap. ·

It has now been found that using ester-based greases proportionately small amounts of the usual fat-forming soaps can be produced if you also have such N-acyl-p-aminophenols used, their aliphatic Part contains 12 to 22 carbon atoms.

The manufacture of these greases is very simple. About 1 to 6 percent by weight of the alkali or alkaline earth soap of a high molecular weight, essentially saturated fatty acid is added to the ester. The mixture is then heated to 177 to 249 ^° C. with stirring. 1 to 2 percent by weight of the N-acyl-p-aminophenol in question is mixed with a mineral oil lubricant and heated ^{to about 121 ° C. with stirring.} When the ester-soap mixture is cooled to about 121 ⁰ C, which Αηιϊηορ1ιβηο1 ^ 01- & 6ΐηΪ5ώ is added. It is allowed to cool to room temperature and a clear, solid fat is obtained.

According to the invention for the production of lubricating greases, the esters of aliphatic, Use dibasic acids of the general composition:

R ¹ OOC-R-COOR ² .

Here, R denotes a divalent aliphatic hydrocarbon radical, such as methylene, polymethylene, ethylidene, propylidene, methyldimethylene, butylidene; R ¹ and R ² are identical or dissimilar hydrocarbon radicals, such as branched-chain alkyl, aralkyl and cycloaralkyl radicals having 4 to 22 carbon atoms. Examples of such esters corresponding to the above composition are the esters of adipic acid, suberic acid, azelaic acid and sebacic acid.

Other "synthetic lubricating oils" which are used as the basis The polyethers, such as polyglycol ethers, and complexes can be used by lubricating greases linear esters obtained by esterification of dibasic acids or glycols with monobasic acids and Alcohols can be obtained, such as the esters of alkylated succinic acid and esters of dioxy acids with the alcohols obtained by the oxo process known from the art. Any alkali or xdalkali soap of the commonly used soap can be used as a soap component.

Use forming acids. Calcium, barium, strontium, sodium or lithium soaps can be used of hardened tears, hardened castor oil, stearic acid, oxystearic acid, oleic acid, tallow, the like Use saturated or unsaturated glycerides of different fatty acids or corresponding mixtures. The mineral oil used as a distributing agent for the aminophenol can be paraffinic or naphthenic Be nature, which according to one of the usual

ίο procedure is cleaned.

In order to produce the lubricating grease compositions according to the invention, about ι to 10 percent by weight of the desired acyl-p-aminophenol mixed with 99 to 90 weight percent lubricating oil. the The temperature is then increased to the melting point of the aminophenol, whereupon it is raised to room temperature lets cool down. During the cooling process, the aminophenol crystallizes in a dispersed state which results in the formation of a stable fat structure.

If you want to make a product with a higher melting point, you can use an ordinary fat-forming one Soap can be added in small amounts, for which one z. B. Alkali or alkaline earth soaps any of the usual used and known for this purpose can use fatty acids. For example you can go for lubrication of the spindle ring in the spinning mill use a fat made from mineral fat that is 2 percent by weight Contains dispersed N-acyl-p-aminophenol and 6 percent by weight lithium stearate. The consistency this fat mixture is equal to that of a mineral fat with a content of 21 percent by weight or more Soap. This shows the economic advantage of using such fats. if if white oil is used in conjunction with mineral fat, the N-acyl-p-aminophenol alone prevents it or in connection with the addition of soap, largely the slow outflow or seepage of the oil during Use or in storage.

In the production of lubricating greases which also contain soap, such as B. in the case of the lubricating greases made from the esters, it is advisable to first prepare a mixture of the ester in question with a soap. Any of the above list can be used as the ester. The soap used is expediently one of an alkali or alkaline earth metal with a high molecular weight, essentially saturated fatty acid. The ester-soap mixture is heated to a temperature of 177 to 249 ^{° C. with stirring.}

The N-acyl-p-aminophenol used is then mixed with a purified mineral oil while stirring and the mixture is ^{heated to about 121 °} C. and mixed with the ester-soap mixture at the same temperature. The entire mass is now cooled to room temperature. This gives a permanent, translucent grease of excellent quality.

Working examples

i. Mix 2 percent by weight of N-stearoyl-p-aminophenol with 98 percent by weight of a mid-continent distillate with a viscosity of 56 SUS at 98 ° C and a viscosity index of 112. The mixture is heated to 135 ° C. with stirring. This solves the aminophenol. It is allowed to cool to room temperature and a solid fat is obtained.

2. Mixing 3.5 percent by weight of N-stearoylp-aminophenol with 96.5 percent by weight of a solvent-treated mid-continent distillate having a viscosity of 43 SUS at 98.9 ° C. and a viscosity index of 112. The mixture is under Stirring heated to 135 ^{° C.} It is then allowed to cool to room temperature and a persistent, translucent fat is obtained.

3. According to the procedure described above, an N-acyl-p-aminophenol is obtained by reaction made of hardened tears with 14 to 22 carbon atoms in the chain with p-aminophenol. 3.5 percent by weight of this product are mixed with 96.5 percent by weight of the oil used in Example 2 and then the same treatment as described in Example 2, subjected. The product is a solid fat of excellent texture.

4. 3 weight percent N-Eraeyl-p-aminophenol was mixed with 97 percent by weight of a naphthenic mineral oil whose SUS viscosity is 500 Is 37.8 ° C. The mixture is heated to 132 ° C. The mass is allowed to cool and an excellent one is obtained smooth fat. go

The key figures obtained according to Examples 1 to 4 Fats are given in Table I.

Table I

Test result of a product produced by thickening a mineral oil with N-stearoyl-p-aminophenol Grease

Penetration depth

(determined in the ASTM grease processor;
¹ Z ₁₀ mm at 25 ⁰ C)

Unedited

Processed:

500 double strokes (piston
with fine perforated plate) ..
100,000 double strokes
(Piston with fine perforated plate)

Drop point (ASTM, ⁰ C) ..

Water solubility

(ioo ° CZ30 minutes) ...

Distributive ability

(determined by a needle point test in a grease syringe)

Filtration residue
through a metal sieve of
1000 χ 250 meshes) ..

Fat sample example af 3 I 4

350

356

345 340 330 345 340 348 118.3 118.3

325

330

332 118.3

nothing

Well:

none

5. 2 percent by weight N-stearoyl-p-aminophenol are made with 98 percent by weight of a polymer

Phenylmethyl silicone oil with a viscosity of 100 SUS at 37.8 ° C. The mixture is heated in a heated fat vessel with stirring to 135 ⁰ C. It is then allowed to cool to room temperature and a solid fat free of any oil excretion is obtained.

In some cases it can be useful to produce a grease whose drop point is slightly is higher than in the case of the product produced according to Example 5. The addition of small amounts of lithium soap raises the dropping point of the grease prepared according to Example 5 to about 121 ° C. In In this case, however, the fat cannot be made by simply mixing the ingredients. The lithium soap must first be dispersed in a mineral oil and this dispersion then in the silicone oil-aminophenol mixture be incorporated. The addition of aminophenol lowers the amount of metal soap otherwise required and lowers the volatility of the obtained lubricant.

6. 4 weight percent lithium stearate in 10 weight percent of a purified mineral oil Heat dispersed to 204 ° C with constant stirring. The mixture is allowed to cool to 115.5 ° C, wherein 85 percent by weight of a phenylmethyl silicone polymer oil having a viscosity of 1000 SUS can be added at 37.8 ° C. One sets ι percent by weight of N-stearoyl-p-aminopbenol to the mixture and then lets the mass cool down without further stirring.

The key figures obtained according to Examples 5 and 6 Fats are given in Table II.

7. To 98 percent by weight of a bleached mineral fat from a melting point of 43.3 ° C., 2 percent by weight of N-stearoyl-p-aminophenol, which by reacting p-aminophenol with commercially available stearic acid, which in turn is extracted from sebum and contains phenitic acid.

Table II

Test results of a lubricating grease prepared according to Examples 5 and 6

Penetration depth ( ¹ Z ₁₀ mm at 25 ⁰ C)

Unedited

Processed:

60 double strokes (piston with

Fine perforated plate)

20,000 double strokes (piston with

Fine perforated plate)

Dropping point ( ⁰ C)

Water solubility

(ioo ° C / 30 minutes)

Fat sample

example

5 I 6

295

315 340

nothing

290

315

345 176.7

nothing

The temperature of the mixture is then brought to the melting point of the aminophenol with stirring, about ii6 ° C, increased. The mixture is then allowed to cool to room temperature without stirring and is obtained a smooth, ointment-like fat of excellent texture.

8. It was found that N-Stearo3d-p-aminophenol has excellent thickening properties, but is little effective as an antioxidant, while conversely N-lauroyl-ρ-aminophenol has little thickening works, but gives the fat mixtures excellent resistance to oxidation. Around To make these properties of both connections usable, according to the working method according to example ι Lubricating greases for spool rings made by mixing mixtures of N-Stearoyl- and N-Lauroylp-aminophenols used:

Thickener

Dropping point
⁰ C

ASTM penetration depth

Vi

Resistance to oxidation (Norma Hoffmann.)

Hours,

up to 0.34 kg / cm ²

Pressure drop

Blank sample: bleached mineral fat

2% N-stearoyl-p-aminophenol

1.75% N-stearoyl-p-aminophenol, 0.25 ° / ₀ N-lauroyl

p-aminophenol

1.5% N-stearoyl-p-aminophenol

1% N-stearoyl-p-aminophenol, i ° / _Q N-lauroyl-

p-aminophenol

% N-Lauroyl-p-aminophenol

41.1
115.6

ΙΙΙ, Ι

io5.6

97.8
93.3

275
275

275
275

275
275

(2.04 kg / cm ² in 70 hours) 70

400 + 400 +

400 + 400 +

Solid lubricants of excellent adhesiveness can also be prepared by small amounts of the above-described N-acylp-aminophenol adds to the resinous masses obtained by propane extraction of a mineral crude oil which is previously deasphalted using propane.

9. 99 percent by weight one made from 33 percent by weight mineral oil and 66 percent by weight one using propane A mixture consisting of a resin extracted from a mid-continent crude oil is 1% by weight N-stearoyl-p-aminophenol heated to 104 to 110 ° C. with stirring. The mixture is allowed to cool and receives a smooth lubricating grease with strong adhesive force and a melting point of 101 ° C. Since the working temperature of the new gear housing is around 65 ° C, the grease is for this use is very satisfactory.

ίο. 99 percent by weight of one made using propane Resin extracted from a Pennsylvanian crude oil, with the addition of ι percent by weight of N-stearoylp-aminophenol heated to 104 to 10 ° C. with stirring. On cooling, an excellent smooth fat with good adhesiveness is obtained.

Claims (12)

PATENT CLAIMS: i. Lubricating greases, characterized in that they consist of a lubricant base, by a small amount of such N-acylaminophenols, preferably N-acyl-p-aminophenols or their mono- or di-ring substituted alkyl derivatives in which the acyl group is thickened Contains 12 to 22 carbon atoms, and possibly a small amount of fat-forming soaps. 2. Lubricating greases according to claim 1, characterized in that that the proportion of N-acyl-aminophenols or their derivatives up to 5 percent by weight amounts to. 3. Lubricating greases according to claim i.unda, characterized characterized in that the N-ayl-aminophenols are those of the general formula HO are, where R is an appropriately aliphatic hydrocarbon radical of 12 to 22 carbon atoms and R ₁ and R _{2 are} hydrogen or identical or dissimilar alkyl groups which contain 1 to 20, advantageously 4 to 15 carbon atoms. 4. Lubricating greases according to claim 1 to 3, characterized in that the acyl group is a palmitoyl, Arachidoyl or stearoyl flu. 5. Lubricating greases according to claim 1 to 4, characterized characterized in that they are N-acyl-p-aminophenols, N-palmitoyl-p-aminophenol, N-arachidoyl-p-aminophenol or contain N-stearoyl-p-aminophenol. 6. Lubricating grease according to claim 1, characterized in that that as a thickener N-stearoylp-aminophenol and N-lauroyl-p-aminophenol can be used. 7. Lubricating greases according to claim 1 to 6, characterized in that they are used as a lubricant base Mineral oils, mineral fats, silicone oils, dicarboxylic acid esters, polyethers or complex linear esters, the by esterification of dibasic acids or glycols with monobasic acids and alcohols can be obtained contain. 8. Lubricating greases according to claim 1 to 7, characterized in that the mineral oils have a viscosity have from 600 to 1000 SUS at 37.8 ° C. 9. Lubricating greases according to claim 1 to 7, characterized in that the silicone oils are polymers of Methylphenylsilicone have a viscosity of 600 to 1000 SUS at 37.8 ° C. 10. Lubricating greases according to claim 1 to 7, characterized characterized in that the dicarboxylic acid esters are those of the general formula R ¹ OOC-R-COOR ² are, where R is a divalent hydrocarbon radical, such as methylene, polymethylene, ethylidene, propylidene or methyldimethylene, and R ¹ and R ^{2 are} identical or dissimilar alkyl derivatives with 4 to 22 carbon atoms, di-2-ethylhexyl-sebacic acid ester being preferably used will. 11. Lubricating greases according to claim 1 to 10, characterized characterized in that they are used as fat-forming soaps alkali or alkaline earth soaps of the usual Fatty acids, especially lithium stearate, contain. 12. A method for the production of lubricating greases according to claim 10 and 11, characterized in that that one mixes the dicarboxylic acid ester with the fat-forming soaps, to the melting point the soap is heated and cooled to 121 ° C, then while maintaining this temperature the N-acyl-aminophenols dissolved in lubricating oils are added and the mixture is cooled to normal temperature. © 509 612 12.55