DE2257638C3 - Lubricating greases - Google Patents

Description

The invention relates to lubricating greases made with polymers, in particular are thickened with polyolefins.

It is known. Lubricating oils using certain Polyethylene either alone or in a mixture with other thickeners ^ for example Alkali metal soap '.], / U thick as described in British patent specification 9 86 192 Lu.

However, it has been shown that greases coated with polyethylene have a "granular" structure, which are very difficult to convert into a smooth grease and that better lubricating greases by using a mixture of olefin polymers can be formed.

According to DT-AS 10 14 694 were already Mixtures of different polyethylenes as thickening) o center! used, and the DT-AS I 054 632 describes the use of a polypropylene manufactured using a special process, but which is insoluble in oil and is crystalline and also does not result in an easily smoothable grease. This also applies to 4s for the lubricating greases described in DT-AS 12 78 056 are and in addition to a mandatory additional thickener and, if necessary a fatty acid metal soap either an oil-soluble atactic polypropylene or an oil-dissolving so Liches atactic ethylene-propylene copolymer contained, while the DT-OS 17 94 111 in first Line with the selection of special particle diameters for those used in lubricating greases Polyolefins employed. <<;

Surprisingly, it has now been found that through the simultaneous use of two specially selected polymers with special properties Lubricating greases can be obtained that is advantageous from the previously known lubricating fto Distinguish between fats by being very slightly gilittnar and do not have a grainy structure.

The invention thus relates to lubricating greases made from a lubricating oil base oil thickened with olefin polymers. which are characterized by dal! as <-5 olefin polymers, they contain a mixture of a tactical polypropylene with a Schmcl / indcx over 50 and a polyethylene with a density of more than 0.94g / cm ¹ , the weight ratio of atactic polyppropylene to polyethylene I: I to 10: 1 is

The polymers with lower molecular weight, however, form lubricating greases with a smoother structure or Lubricating greases that can be smoothed out more easily, so that the choice of polymer normally depends on the intended use Purpose of the grease depends. For general-purpose lubricating greases, e.g. lubricating greases for the lubrication of closed gears, however, a lower polymer content is preferred.

The melt index of polypropylene is above 50. In alactic polypropylene, the amount is present isotactic polypropylene preferably below 107 ... The melt index of the polypropylene can according to the Test method BS 2782, Method 105C or ASTM D 123 B can be determined. The MoW.ular weight of the polypropylene is preferably less than 100,000.

The polyethylene preferably has a molecular weight (weight average) of 20,000 to 500,000, in particular 50,000 to 250,000. The total weight of polymer in the lubricating grease is 1 to 20%, in particular 3 to 15% based on the total weight of the grease.

The weight ratio of atactic polypropylene to polyethylene is in the range from 1: 1 to 10: 1, in particular in the range from 2: 1 to 5: 1.

The lubricating greases according to the invention preferably have a penetration above 300, in particular a penetration of 310 to 5 (K). The penetration of the lubricating grease can be determined according to the test method ASTM 217-68 can be measured.

example

Lubricating greases were made from two different Schmicrölgiundölcn as follows: Half of the total amount of the oil and the polyethylene were heated to KK) C. Then the atactic polypropylene was slowly added while heating to 150 ° C. The batch was held at 150 ° C. for one hour so that the polymers could swell and partially dissolve. The batch was heated to 180 ° C. and held at this temperature for at least 30 minutes, during which the polymers were completely dissolved. The remainder of the lubricating oil was added and the batch was cooled as quickly as possible, thereby forming the lubricating grease. L ¹ Us of lubricating grease was circulated through a homogenizer at 80 ° C. and thereby smoothed.

In Tables I and 2, the starting materials are given which are used for the production of the products mentioned in Table 3 Greases have been used. Table 4 shows the influence of Schmclzinde.x on the structure of the grease.

In the tables, "smooth" means essentially an homogeneous grease with a smooth consistency. "Grainy" means the presence of grains or particles in the grease, and "rubber = like" means a structure that is tougher and is spongy or more elastic than the well-known "shoulder-like" structure of most lubricating greases. Further are called when removing part of such Lubricating fat formed from the main mass of threads that are still related to the I lauptniasse of the lubricating fat and have elastic properties.

Table 1

Characteristic number of the polymers

Polymer quality Melt density Molecular type index g / ml weight

Λ tactical

Polypropylene B 0-20
20-50
<50

Polyethylene
H
III
IV

XGR 369 type 9
Type 50

0-20 0.87 20-50 0.87 <50 0.87

0.9 5

0.96 0.96 0.96

Melt index; BS 2782, Method 1050 Door Polyethylene; ASTM D 1238 Door Polypropylene at 190 C Molecular Weight: Intrinsic Viscosity Method Density: BS 2782, Mathode 509A

Table 2

9000/10000 (isotacti- io shear share about 6%)

150000

88000 ^{l: <} 70000

Key figure of the lubricating oils

oil Kinematic viscosity, cS

37.8 C WJ C 99 C

1077
137.2

242.6
40.49

41.33 10.27

Viscosity index

76 43

Table 3

Key figures for Sr.hmierlettes made from arctic polypropylene B (melt index > 50)

1-ett- Oil Λ tak Poly r- Oil type Aüiktisches Total- Poly- Walk structure I. Polypropylene I 411 slightly grainy, light Remarks [smoothing fat he / cich- lyp table ethylene Type U poly propy pene- I. rubbery Fat can be smoothed out tion Poly meri- len / poly- 1 I 441 desg'equal will propy Schmclzin- satc ethylene- tion I. Weight% 1 442 slightly grainy len (U), dex area Relationship I. I 436 smooth (each - "A Type weight- ' Y 0-20 ',, CjCW. - "/., nis 1 5.50 1 445 smooth 4/1663 Y 4.20 II 0.80 0-20 5.00 5.25 I. 4.40 401 grainy. Fat can be smoothed out 20-50 I. 5.50 410 slightly rubber will, 4 / Ι663Λ 3.93 Il 0.75 4.68 5.25 1 473 good slightly rubbery 4/1661 Y 4.20 III 0.80 > 50 5.00 5.25 1 5.50 372 smooth Fat can be smoothed out 4/1660 Y 4.20 IV 0.80 > 50 5.00 5.25 7.20 411 smooth 4 / 1660Λ 3.93 IV 0.75 4.68 5.25 443 smooth 1/1739 Z 9.98 Il 1.98 11.96 5 420 slightly grainy Fat can be smoothed out 4/1668 7.43 Il 1.48 8.91 5 431 slightly grainy still 4 / Ι668Λ 5.81 II 1.16 6.97 5 401 slightly grainy light, elastic 4/1669 Z 8.75 III 1.75 10.50 5 422 slightly grainy Fat can be with some 4 / Ι669Λ 7.66 III 1.53 9.19 5 Difficulty smoothed 4/166915 7.17 III 1.43 8.60 5 will 1/1751 Z 10.01 IV 1.98 11.99 5 Walkpene structure 4/1667 8.75 IV 0.75 10.50 5 (ration Fat is easy to get 1/1778 7.53 IV 3.67 11.00 2 smooth 1/1769 6.67 IV 3.33 10.00 2 Table 4 KinfliiU of the melt index 373 description 436 Remarks of the Schniii! 436 I'ettcs 443 438 4/1629 grainy, gunimi-like | very difficult to 4 / 1629Λ likewise 4/1630 slightly grainy. rubbery 4/1631 slightly rubbery 4/1657 likewise

continuation Oil type AUikiisiiies
Type U
Schmel / in-
ücxhcrcich Polypropylene
Cicw.- ".. Walkpene
lruiion structure licnicrkungcii Hey / eichnuni!
of the lubricant
fat Z 0-20 15.00 173 very grainy,
rubbery iiExtremely difficult
/ u sliding l ';: tt 4/1633 0-20 9.40 364 likewise 4 / 1633A 20-50 15.00 39S slightly grainy,
rubbery l ^: eu liilit itself with
some difficult
smooth. 4/1634 20-50 11.30 440 likewise 4 / 1634Λ > 50 15.00 420 slightly gunmetal I'ctt be gliiti 4/1635 > 50 12.00 428 dcsclwichcii 4/1454

Claims (3)

Patent claims: ;. Lubricating greases made from one with olefin polymers thickened lubricating oil base oil, characterized in that that they are a mixture of an atactic polypropylene as Olellnpolymerisate with a melt index above 50 and a polyethylene with a density of more than 0.94g / cm ' contain, the weight ratio of atactic polypropylene to polyethylene 1: 1 to 10: I. 2. Lubricating greases with a penetration of 310 to 500, according to claim I. 3. Lubricating greases according to claim I or 2, characterized in that they are an alaklisches polypropylene with a molecular weight of less than 100,000.