DE2306663A1 - GREASES - Google Patents

Description

DipL-Ing. P. WIRTH Dr. V. SCHMIED-KOWARZIK DlpL-Ing. G. DANNENBERG Dr. P. WEINHOLD · Or. D. GUDEL

281134 6 FRANKFURT AM MAIN

TELEPHONE C0611)

287014 GH. ESCHENHEIMER STRASSE

Case 79
Vd / Sch

LABOPINA S.A.

rue de la Lo i, 31 -

1040 Brussels

Belgium

Lubricating greases.

309835/0900

The present invention relates to new, particularly 'permanent lubricating greases and to a method of production the same.

So far, most lubricating greases have been made from miner al ie just oüe: c synthetic oily bases or base oils Addition of thickeners to achieve the desired Made consistency. Soaps of fatty acids or inorganic agents such as colloidal « Silicon oxide, bentonite, etc., are used. '

These known lubricating greases are gels, the thickener being a rush forms which absorbs the oil. In the production of a homogeneous and stable gel it comes across However, due to various! factors, such as the type the thickener, the type of base oil, the respective Amount of these components, the manufacturing process for the Grease, etc., for difficulties. The influence of the various Factors is still largely unknown.

The introduction of polymers into the lubricating grease therefore has to improve some of its properties led to new difficulties. For example, there are some olefin polymers namely polymers of ethylene or propylene or copolymers of ethylene with higher 1-olefins, suggested as a thickening agent, but the gels obtained are not stable enough and break under mechanical stress Stress, whereby a product that is too flowable is formed (see U.S. Patent 3,112,270). On the other hand, it was observed that polyisobutylenes produced by "low pressure polymerization are not suitable as a thickening agent and attempts to produce usable lubricating greases from these polymers have failed (see German Patent 1,091,683).

It has also been suggested in the lubricating greases. "Certain Bring in polymers to prevent the fats from escaping and the

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To prevent the oil from separating out of the network formed by the thickener. Such compositions generally contain less than 10 to 12 % polyisobutylene with an average molecular weight of over 250 _5, in particular from 10,000 to 11,000.

The introduction of these polymers into the lubricating greases ... -

suggests a new measure which affects the manufacture

of these fats and affects some of their properties *. It has also been found that the introduction of polymers into the fats is a critical process, and. aside from that the products obtained have some drawbacks in terms of their performance. .

Improved lubricating greases have now been developed which eliminate these skin parts. The object of the present invention is the creation of homogeneous, permanent and effective lubricating greases. Another object of the present invention is the creation of a simple process for the production of lubricating greases for which lower quantities of thickening agents agents and conventional additives are required to obtain the desired performance.

The lubricating greases according to the invention contain about 2 to 15% by weight of aluminum soap, about 25 to 98% by weight of a polymer monoolefinic hydrocarbons have 4 carbon atoms and an average molecular weight of about 300 to 2,500 and about 0 to 60 wt. 56 lubricating oil.

The process according to the invention for the production of these lubricating greases includes:

- The dispersing of about 2 to 15 wt .- ^, based on the Weight of the composition, of aluminum soap in about 10 to 50% by weight of a polymer of monoolefinic hydrocarbons having 4 carbon atoms and an average molecular weight from about 300 to 2,500 at a temperature

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from about 15 to 50 ⁰ G,

- the increasing heating of this dispersion,

- the addition of about 0 to 60 wt. fo lubricating oil as soon as a temperature of about 90 to 110 ⁰ G is reached,

- the slow addition of about 15 to 48 wt .- ^ of a polymer of olefinic hydrocarbons with 4 carbon atoms and an average molecular weight of about 300 to 2,500, so the temperature which is kept at the same level during the entire addition of polymer, about 150 has reached 180 ⁰ C,

- The cooling and homogenization of this mixture at about 10 to 35 ⁰ C.

It has been found that the lubricating greases according to the invention, which can contain up to 98% by weight, based on the lubricating grease, of a polymer of butene or isobutylene with a relatively low molecular weight mixed with an aluminum soap as thickening agent, are pliable, homogeneous and particularly stable which makes them ideally suited as lubricating greases. This result is unexpected, since it has been customary in the prior art to use polymers with a high molecular weight and only add small amounts of them in order to avoid an adverse effect on the resistance and the lubricating effect of the greases.

The aluminum soap or the thickener are generally used in amounts of about 2 to 15 wt .- $, in particular from about 3 to 8 wt .- $, based on the total weight of the lubricating grease, used. This aluminum soap is mostly a saturated or unsaturated higher aliphatic soap Carboxylic acid with about 12 to 20 carbon atoms, e.g. stearic, oleic, ricinoleic or palmitic acid. It can also be mixed Aluminum soaps, which are made from a higher aliphatic Carboxylic acid and from a carboxylic acid having a low molecular weight can be used. Such aluminum

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Soaps are e.g. soaps of benzostearin, toluostearin or Aiietopaliaitip.aäuren. The latter is therefore "for example a mixture of a soap of acetic acid with a soap of palmi ~ tiii .:: acid, this mixture preferably at least about 50% by weight of the soap which contains acetic acid.

It ϊ / ΰταβ found that when using alkali or alkaline earth soap Instead of an aluminum soap while maintaining the other conditions, the Seiraierfett is somewhat "softer". Dareus shows that the amount of soap required to produce a fat with a certain consistency at YerwenduRg an alkali or alkaline earth soap is higher than that of Aluainiuiase soap; the latter is therefore more economical and will preferred for this reason.

Any mineral, aromatic, or naphthenic oil can be used as a lubricating oil before oil can be used, being a strong naphthenesehes Oil for the production of lubricating greases with a high thermal stability is preferred. Synthetic lubricating oils such as esters of sebacic or adipic acid can also be used and of alcohols with about 6 to 12 carbon atoms, like 2-ethylhexanol. It won't get more than about $ 60 oil, most of the time between about $ 10 and $ 50 based on the weight of the Grease, used. In general, the consistency of the Sehmier fat increases as the amount of oil decreases. Also is it is advantageous to use oils or mixtures of oils with an ¥ iskositätsindex between about 10 and 100 or even higher, preferably between about 30 and? 0, to be used.

The most frequently used linear polymer of butene or isobutylene is a hydrogenated or unhydrogenated liquid homopolymer with an average molecular weight of about 300 to 2500. This polymer can be the only oil-like constituent of the grease and can be present in an amount of Ms of about 98% by weight be. On the other hand, at least 25 & possibly ^r «- $ of a polymer can be used to produce a lubricating grease with high consistency, durability and performance. Mixtures of the polymers can also be used, namely a mixture of two or more such polymers

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- ⁶ - 23066B3

n with a different molecular weight or mixture ^ ans non-hydrogenated and hydrogenated polymers.

In the preparation of the OCE erf Indungsgemäßen - greases advertising _■: ■ AEAI about 2 to 15% Aluminiüraseife, based on the weight - _v ies fat, in about half the. required. Amount of polytates or polyisobutylene, ie in about 10 to 50% by weight. des, polymer, dispersed. This dispersion takes place with constant stirring at ... a temperature of about 10 to. 5P ° C, Bie mixture wird- increasingly heated "and if it has reached the temperature of about 110 ^p C, the oil may be used is added. Then, when the temperature has reached about 150 Mp 180 ° G, the remaining amount of the required polymer is gradually indicated with stirring, the temperature being kept between about 150 and 180 ° C. As already mentioned above, can . it is other than -handeln in the latter polymer in the first stage of Yer- -fahrens Then, the mixture is cooled and when it has reached Zlmraerteiaperatur, it is -homogenisiert in a colloid mill or other suitable homogenizing ^_.:

Other ingredients can be added to the lubricating grease, "- e.g. high pressure additives, anti-corrosion agents, dyes, polymers with a high molecular weight," which improve the adhesion or binding capacity of the grease, for example on metal surfaces, such as polyisobutylene with a molecular weight of more than about 100 000; the amount of these additives is generally not more than 2 to 3 weight per cent of the Sehmier fat.

It has also been found that the invention Sebmler grease en smaller amounts of aluminum elf than ¥ er— thick ^ BgsBittel and additives to improve the adhesion are needed than with the well-known Selauier— fat »to the same. Achieve result.

■■ - :. ■■; ■■■■ .. - ⁷ - '

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The components of the lubricating grease according to the invention, that is the aluminum soap, the polymer of the C. »Mono ole? n and oil as possibly added lubricating oil, if they unique mixtures with special properties are used in the proportions given above. if if this polymer is replaced by another homologue or this soap, this has a detrimental effect on the quality of the grease.

The following examples serve to explain the Invention. In these examples the following tests are mentioned:

ASTM D 217-52T or penetration test, which is used to determine the consistency

and the mechanical resistance of the • grease is measured.

ASTM 2266 for testing anti-wear properties

of lubricating greases (4-ball method, 1800 rpm, 1 hour, 75 ° C and 40 kg / cm ² ).

example 1

5 parts by weight of aluminum stearate and 42 parts by weight of non-hydrogenated polyisobutylene having an average molecular weight of 460 were mixed at room temperature. This mixture was then heated with stirring as quickly as possible. When the temperature of about 120 ⁰ C had been reached, 20 parts of naphthenic oil were added to a Tiskositätsindex of 70th The mixture was heated further and, when the temperature had risen to 170 to 180 ° C., 32.8 parts of unhydrogenated polyisobutylene with an average molecular weight of 730 and 0.2 parts of polyisobutylene with an average molecular weight of more than 100,000 were added and after admitted. During this addition the temperature was maintained at about 175 ° C and stirring was carried out. Then the biting grease was placed in a kettle. The cooled fat was then poured into a blender and passed through a homogenizer.

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The grease was pliable, tough, homogeneous, pale colored and transparent. The hardness "was 285 (in 1/10 mm at 25 ° C, see ASIM test 217-52T) if mechanically untreated Grease and grease treated with hot 60 strokes.

The wear index (ASTM-Iest 2266) was 0.72.

A comparison showed that for a grease which did not contain polyisobutylene with a low molecular weight, a larger amount of aluminum soap (8% by weight instead of 5 %) to achieve the same degree of hardness and a larger amount of additive to improve the adhesiveness ( 1 wt .- $ instead of 0.2 f ») was required. On the other hand, 1 fo polyisobutylene, the wear index was in this grease containing 8 wt. -Fa aluminum soap having a molecular weight of more than 100, 000 and contained 91 $ 1.07 mineral oil.

It is clear from this that by using polyisobutylene with a molecular weight of less than 2,500 in the manufacture of the grease lesser amounts of ■ thickeners and additives are required, the Sehmierfett, however, has better lubricating and anti-wear properties owns.

Example 2

A grease was made from:

46.8 wt .- δ of non-hydrogenated polyisobutylene with an average Molecular weight of 460,

48.0 wt .- $ unhydrogenated polyisobutylene with a medium Molecular weight of 730, 5.0 wt .- $ aluminum stearate,

■ 0.2 wt. -Fo additives for improving the adhesiveness.

- 9 30983570900

This grease was pliable, homogeneous, colored and tough and had a penetration index of 289 and a wear index of 0.63.

For comparison, a grease was produced which was also free from mineral oils, but instead of lithium soap contained by alurainiura soap. See when using 12 wt .- $ lithium soap, this grease was less harsh, the penetration was 319.

Example 3

A similar grease was prepared by following the procedure of Example 1, but with 39.8 parts by weight of one hydrogenated polyisobutylenes with an average molecular weight of 44-7 and 35 parts by weight of a hydrogenated polyisobutylene with an average molecular weight of 6> 33.

This grease had a slightly lower consistency (penetration: 296) but had anti-wear properties were better (wear index: 0.68).

Example 4

The procedure of Example 1 was repeated, but using 74.8 parts by weight of polyisobutylene with a average molecular weight of 500.

The grease had remarkable mechanical resistance; the penetration was:

294 for mechanically untreated fat,

295 for mechanically treated grease (60 blows).

The anti-wear properties were also remarkable; the wear index was 0.70.

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Bites) iel 5

The procedure of Example 1 was repeated, but replacing the mineral oil with a synthetic oil (di-2-ethylhexyl sebacic acid ester) "was replaced.

The grease also had remarkable anti-wear properties (Wear index 0.70), but a slightly lower consistency (penetration: 340).

Examples 6 to 9

There were 4 greases made from naphthenic mineral oils (viscosity index: 70), non-hydrogenated polyisobutylene, aluminum soap and an additive to improve adhesion (polyisobutylene with an average molecular weight of more than 100,000).

The respective weight ratios of these components in the fats and the test results are in the following table listed.

The molecular weight of the polymer used is according to Abbreviation PIB given.

Ex . 6th Ex . 7th Ex . 8th Ex . 9 PIB 300 33 PIB 670 34 72, 8th 71 8th 41, 8th Al stearate 8th 5 Al-acetopalmitate 7th 3 5 mineral oil 57, 8th 20th 20th 20th Adhesion
better 0, 2 0, 2 O, 2 O, 2 Intrusion
(untreated fat) 301 287 285 304 Wear index 0, 74 0, 71 O, 72 O, 68

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The main characteristics of these greases are their consistency and anti-wear properties.

For comparison, a lubricating grease made from 54.8% by weight of mineral lubricating oil , 5% by weight. -fo aluminum stearate, 10 Gew .- ^ polyisobutylene with an average molecular weight of 670 and G-ew. - ° / o Polyisobutylene with an average molecular weight of 3500 produced. As a result of the addition of the last-mentioned polymer, the fat could hardly be worked or applied mechanically at low temperatures. The same disadvantage had greases which contained polyethylene with a low molecular weight and polyhexane. On the other hand, however, suitable greases cannot be made from high molecular weight polyolefins.

The same grease was prepared as in Example 6, but using calcium stearate instead of aluminum stearate. This grease had a much lower consistency.

These results clearly show that the lubricating greases according to the invention, due to the use of those indicated above Components in certain proportions have greatly improved properties.

309835/0900

Claims (4)

2306B63 P a t ent a η s. Υ r ü eh. E 1. Lubricating grease, characterized in that it is essentially about 2 Ms 15 wt .- ^ of aluminum soap, about 25 Ms 98 wt. -Io of a polymer of monoolefinic hydrocarbons with about 4 carbon atoms from the group: hydrogenated and non-hydrogenated polybutene and polyisobutylene having an average molecular weight of about 300 Ms 2500, and about 0 to 60 % by weight of lubricating oil carriers. 2. Schiaierfett according to claim 1, characterized in that there is essentially about 3 to 8 <-Ge \ f, -fo of aluminum soap, about 35 to 97 wt .- ^ of the polymer of mono-olefinic hydrocarbons and about 0 to 57 wt. '- ^ on the lubricating oil carrier. 3. Lubricating grease according to claim 1 - 2, characterized in that that as aluminum soap it contains an aluminum soap of a carboxylic acid with about 12 to 20 carbon atoms * 4. Process for the production of lubricating greases according to claims 1-3, characterized in that it comprises the following stages includes: Dispersion of about 2 to 15% by weight, based on the weight of the composition, of aluminum soap in about 10 to 50% by weight of a polymer of monoolefinic hydrocarbons having about 4 carbon atoms and an average molecular weight of about 300 and 2500 at one temperature from about 15 to 50 ⁰ O, 30 983S / 0900 ■ ■ ■ · - 13 - - aHraählichen heating of this dispersion, - Adding about 0 "to 60 wt .- ^ lubricating oil carrier, as soon as a temperature of about 90 to 110 ⁰ C is reached, - Slow addition of about 15 to 48 C-ew .- ^ of a polymer olefinic hydrocarbons with about 4 carbon atoms and an average molecular weight of about 300 to 2500, as soon as the temperature, which is kept at the same level during the entire addition of the polymer, has reached about 150 to 180 ⁰ O, - Cooling and homogenizing this mixture at about 10 to 35 ⁰ C. 309835/0900