DE1276275B - Grease - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN 4MWm> PATENT OFFICE

EDITORIAL

Int. α .:

ClOm

German KL: 23 c-1/01

Number:
File number:
Registration date:
Display day:

P 12 76 275.3-43 (S 95701)

February 26, 1965

29th August 1968

The invention relates to a lubricating grease having good extreme pressure properties within a wide range Temperature range, which is easy and economical after the direct transfer process can be produced.

The lubricating grease according to the invention, which is a colloidally dispersed, after activation with contains a mineral acid with a waterproof coating, is characterized by that it is a clay coated with an amino amide mixture, which by reacting a predominantly saturated fatty acid or a fatty acid mixture with 8 to 20 carbon atoms with a polyethylene amine or polyethylene polyamine mixture, as well as lubricant additives contains well-known sodium sebacate and phenylnaphthylamine.

Compared to known lubricating greases, which by adding an amino compound such as melamine or Urea, which is a thermosetting amine-aldehyde ao Able to form resin, or from hexamethylenetetramine and a strong mineral acid to the liquid Clay hydrogel and mechanical separation of most of the water before adding one volatile, water-miscible organic liquid and further work-up using the solvent displacement process, the lubricating greases according to the invention offer the advantage that only a short-term heat treatment of about 15 minutes is required.

In addition, the combined addition of sodium sebacate and phenylnaphthylamine is special Advantages in terms of pressure resistance at high temperatures and resistance to an oxidative decomposition of the lubricant.

The lubricating oil base can be selected according to the working conditions intended for the lubricating grease will. In this regard, most mineral oils are for high temperature uses stable up to temperatures of about 149 ° C and synthetic esters are useful up to temperatures from about 177 to 204 ° C.

At temperatures above 204 ° C, liquid organosilicones or halocarbons can be used as the lubricating oil base be used. Examples of halocarbons are given in U.S. Patent 2,679,479 at. Suitable are e.g. B. methyl silicone oils and methyl phenyl silicone oils.

Methylphenyl silicone oils are preferred because of their greater thermal stability. In all of these oils can replace some of the methyl radicals with other organic radicals or inorganic atoms; z. B.

Grease

Applicant:

Shell International Research

Maatschappij N.V., The Hague

Representative:

Dr. E. Jung, patent attorney,

8000 Munich 23, Siegesstr. 26th

Named as inventor:

Harold Albert Woods, Martinez, Calif .;

Harvey Eugene Hook,

Danville, Calif. (V. St. A.)

Claimed priority:
V. St. ν. America February 28, 1964
(348 276)

some of the methyl radicals can be replaced by alkyl radicals, hydrogen or halogen atoms.

Particularly suitable ester oils are pentaerythritol esters of saturated fatty acids.

If the grease is used at either extremely low or extremely high temperatures, thus the addition of at least 30 percent by weight of a diester of azelaic or sebacic acid improves or a mixture thereof derived from an aliphatic monohydric alcohol to e.g. B. one of the two preferred groups of the synthetic lubricating oil base is largely performance of the grease, for example down to temperatures of -73 or 93 ° C. In the case of the Polysiloxane oils contain the lubricating oil base preferably 70 to 90 percent by weight (especially at least 80, e.g. B. about 85 percent by weight) diester, based on the oil. When a pentaerythritol ester is a saturated fatty acid is used as the lubricating oil base, the lubricating oil base preferably contains 30 to 50 percent by weight (especially at least 40 percent by weight) of diester, based on the oil.

The clays used according to the invention can have an essentially basic exchange capacity, preferably about 60 to 100 meq equivalents of the exchangeable base per 100 grams of clay.

Examples of the clays are montmorillonites, especially sodium, potassium, lithium and others

809 598/525

Bentonite, ζ. B. Wyoming bentonite, magnesium bentonite (hectorite) and saponite. The tone is preferred pre-treated to remove most of the gait normally associated with it. The clay forms a hydrosol with water; with a content of preferably 1 to 5 percent by weight Clay results in a hydrosol that is relatively fluid and easy to transport, e.g. B. by Pump.

In order to activate the clay, it is preferably further treated in the hydrosol form just mentioned. The amount of mineral acid added should be at least equal to the exchange capacity of the clay for bases. If phosphoric acid is used, an amount of about 4 to 12 percent by weight, based on the clay. Preferably the clay is 45 to 70 percent by weight Aminoamide based on the weight of the dry clay coated.

The amino amide is preferably used under conditions in which the amino amide is liquid acidified clay hydrosol added.

The aminoamide, when freshly made, is a viscous liquid that turns into a soft, granular paste that is easy to handle on standing. The amino amide can be formed by heating the fatty acid with a polyethylene polyamine to a temperature of 200 to 225 ° C. for 1 to 4 hours. In practice, C ₈ _ ₁₈ fatty acids are used containing at least 80 percent by weight of saturated fatty acids and preferably have an iodine value below 50. The fatty acids in coconut oil are preferred. The polyethylene polyamine can be about 40% amidated. For example, the amino amide can be formed with 35 to 45% nitrogen active material. In practice, the polyethylene polyamine is usually the residue in the production of ethylene diamine. Such a residue consists of a mixture of ethylene amines boiling above the boiling point of triethylenetetramine (e.g. tetraethylene pentamine) diluted with a small amount of diethylenetriamine to obtain a low viscosity suitable for convenient handling. This polyamine mixture can also contain very small amounts (e.g. 5% or less) of ethylene diamine. Such a polyamine mixture has the following properties:

Specific weight at 25 ° C .. 0.995 to 1.020

viscosity

(with 25% thinner) 75 to 250 cP volatility, percent by weight .. not more than 2.0

Mud and sediment,

Weight percent 4 to 7

The mixture of polyamines can contain 20 to 80% (preferably less than 50%) diethylenetriamine The remainder consists of polyethylene polyamines with an average molecular weight from 220 to 450.

A lubricating grease that can be produced according to the invention preferably contains 0.75 to 1.25 percent by weight Sodium sebacate and 0.75 to 1.25 percent by weight phenylnaphthylamine (especially / Ϊ-phenylnaphthylamine), based on the weight of the grease. The grease can also contain other antioxidants contain except phenylnaphthylamine, z. B. phenothiazine or diphenylamine. Explain the following examples The invention.

example 1

The greases A, B, C and D are used a neutral mineral lubricating oil with a viscosity of 500 SUS at 38 ° C as a lubricating oil base with greases B, C and D for comparison.

The compositions of greases A, B, C and D are shown in Table I below.

Table I.

Lubricating greases

Weight percent

Weight percent

Weight percent

Weight percent

Oil based

volume

Coating agents,

phosphoric acid

/ ^ ■ Phenylnaphthylamine

Sodium nitrite

Sodium sebacate,

90.2 4.8 2.7 0.3 1.0

1.0 90.5
4.8
2.8
0.3
1.0
0.6

87.6
6.6
3.9
0.5
0.8
0.6

87.1
6.6
3.9
0.5
1.3
0.6

The following process is selected for the production of every lubricating grease:

A 2% aqueous suspension of the hectorite clay from the gangue is heated to 71.degree. to The heated suspension is diluted phosphoric acid, amino amide as a coating agent and the oil base admitted. After these components have been completely mixed, agglomerates or "Pearls" formed with an accompanying, separate aqueous phase. The agglomerates are dated Freed water and heated to 132 ° C, at the same time an aqueous solution of either sodium nitrite or sodium sebacate added slowly. After the mixture has heated to 132 ° C for about 15 minutes the water content had decreased somewhat due to evaporation. Add to the hot mixture Phenylnaphthylamine added. The mixture is then cooled and ground to make the finished grease to obtain.

Each grease is subjected to a high temperature stress test. In this test (called "Four Bearing Rig Test") four bearings are sealed with the same grease composition are mounted on a single shaft that

powered by a motor of 0.507 hp. The test conditions are:

On each bearing the same radial load is applied to rotation speed .... 3,600 rpm

and by means of a spring-loaded _{separator the same axial T} ^{6 B} -Μ ο ο Λ

exposure brought into effect. The test bench lemperaxur. i4y <_

is enclosed in an insulated housing, the 5 load, axial ⁵ JiZ * L, ^g

due to the circulation of heated air on the load, radial 90719 kg

desired test temperature is heated. The test stand In addition to the "Four Bearing Rig Test", work will be carried out then 20 hours at high temperature and subject the greases to an oxidation test in the bomkühlt in 4 hours to room temperature. Every benrohr subjected to the extent of the oxy-bearing works to the point of failure, which is caused by an iodative decomposition by means of the pressure drop in the of the following incidents occurs: Inside the bomb tube at different time intervals is measured.

a) rapid temperature rise in the warehouse,

b) Bearing seizure or The results of this test are as follows

c) Failure to start after a standstill. ¹ S Table II reproduced.

Table II A. Lubricating greases
BIC 860
0.70
1.26
1.54
1.68
1.89 D. 1760
0.49
0.56
0.63
0.70
0.77 740
0.63
0.84
0.84
1.05
1.19 960 "Four Bearing Rig Test"
Average bearing life in hours *)
"Oxidation test" in the bomb tube
Pressure drop, kg / cm ²
after 100 hours after 200 hours after 300 hours after 400 hours - after 500 hours

*) Based on the number of 20-hour work cycles.

The grease A according to the invention shows a
superior behavior in terms of resilience
and the resistance to oxidation.

Example 2

The lubricating greases E, F and G according to the invention,
the composition of which is shown in Table III, are produced according to the method described in Example 1 and the Military Specification MIL-G-7118 A »Grease; Aircraft and Actuator Screw for Low and High Temperatures «tested in accordance with. All three greases pass these standard tests. In particular, the lubricating greases E and F can be used for bearing lubrication in the entire temperature range from -73 to + 177 ° C under severe conditions, which is not possible with known lubricating greases.

Table III

Weight percent

Lubricating greases

F percent by weight

Weight percent

oil based

Polysiloxane oil (DC-510)

Pentaerythritol esters of saturated aliphatic acids

Di-2-ethylhexyl azelate

Di-2-ethylhexyl sebacate

Di-2-methyl-1-butyl azelate

Hectorite clay

Coating agent *)

phosphoric acid

Phenyl - /? - naphthylamine

Sodium sebacate

Phenothiazine

Diphenylamine

Metal deactivator

*) Reaction product of polyamines and coconut oil fatty acids.

51.1
37.0

5.3
3.2
0.4
1.0
1.0
0.5
0.5

13.5 75.3

5.5 3.3 0.4 1.0 1.0

61.5 26.3

5.5 3.3 0.4 1.0 1.0 0.5 0.5 0.03

Example 3

The following greases are tested for the mean Hertz load test (see Federal Test Method Standard No. 791 a, Method 6503) to compare the properties of lubricating greases under heavy load soap-based (with and without extreme pressure

Additives) and the lubricating greases that can be produced according to the invention without any extreme pressure additives subject.

The results of the “Mean Hertz Load Test” are shown in Table IV below.

Table IV lithium
soap
Diester
5%
127
178
44 lithium
soap
Diester +
Pentaery
thritester
5%
142
158
46 volume
Diester
none
158
158
53 volume
Diester +
Pentaery
thritester
none
157
178
57 M. volume
Diester +
Polysilicon
oxane oil
none
178
178
59 Characteristics
of the individual components
Thickener
Oil based Extreme pressure additive
(Molybdenum sulfide)
"Mean Hertz Load Test"
Start of seizure, kg
Welding point, kg
Mean Hertz Load (MHL) Lubricating greases
HII [JIK j L lithium
soap
Diester
none
60
112
25th

The lubricating greases that can be produced according to the invention (e.g. the lubricating greases K, L and M) are the lubricating greases Far superior to soap-based greases, even if the soap-based greases are substantial amounts contain more effective extreme pressure additives.

35

The lubricating greases according to the invention thus have the following technical advantages:

1. They have better load properties (without the use of extreme pressure additives) than the corresponding soap-based greases and also many thickened with clay, special lubricating greases containing extreme pressure additives;

2. in the "Mean Hertz Load test" of working ^4S agree beginning match of seizure and the welding point substantially, as a comparison with the large deviation of these points for the greases soap-based shows.

50

Both of these benefits are of great importance as there is a loss of metal prior to bearing failure is reduced and thereby a very satisfactory operation of the camp over a maximum period of time is guaranteed without a prolonged period of poor storage behavior occurring, which is at the limit of portable work.

Claims (1)

Claim: Lubricating oil-based grease containing a colloidally dispersed one after activation Clay provided with a mineral acid with a waterproof coating, characterized in that that it is a clay coated with an amino amide mixture, which by reacting a predominantly saturated Fatty acid or a fatty acid mixture with 8 to 20 carbon atoms with a polyethylene amine or Polyethylene polyamine blend has been made, as well as known as lubricant additives Contains sodium sebacate and phenylnaphthylamine. Considered publications:
German interpretative document No. 1 086 839. 809 598/523 8.68 © Bundesdruckerei Berlin