Lubricating greases are solid or semiliquid products of a dispersion from a thickening agent in a liquid lubricant. Through the delivery of a sufficient quantity of liquid lubricant by slow separation they avoid friction and wear over wide temperature ranges and over long periods of time. At the same time they are used as sealing against water and foreign particles. Lubricating greases are, for example, used for lubrication of machine elements as roller and journal bearings, conveying chains and ropes as well as gear units.
Metallic and alkali soaps as thickeners
The use of ready-made metallic and alkali soaps avoids the critical reaction phase during grease production. The soaps are solved in the basic liquid, by which small quantities of residual moisture are stripped. By special temperature control the grease structure is obtained, followed by mechanical processing (addition of additives, trituration, aeration etc). Depending on which grease properties are required, the metal soaps can be used individually or in combination. Ready-made metal soaps are of special advantage in connection with synthetic or natural esters as base stocks.
LIGA LITHIUM-12-HYDROXY-STEARAT
LIGA LITHIUMSTEARAT
Most important soaps for the production of lubricating greases. Applied in mineral oil, vegetable oil (e.g. castor oil, rapeseed oil) or in synthetic base stocks (e.g. ester oils, PAO). The application quantity for NLGI-class 2 is approx. 8-10%.
Lithium base greases are preferred lubricants for virtually all roller bearing types in the operative range between -40 and +140°C, but also very much suitable for friction bearings, joints, slide rails, etc. They are characterized by good adhesiveness and good corrosion protection. Very high fulling resistance and drop points of 200°C are achieved by using LIGA LITHIUM-12-HYDROXYSTEARAT. With LIGA LITHIUMSTEARAT grease types for lower mechanical load are gained, whereas the drop points can be realized to approx. 180°C.
LIGA CALCIUM-12-HYDROXY-STEARAT
LIGA CALCIUMSTEARAT 600
LIGA CALCIUMSTEARAT 800
LIGA CALCIUMBEHENAT
LIGA CALCIUMLAURAT
For the production of lime base greases of NLGI-class 2 approx. 15-18% soap share is needed. Here mainly mineral oil and vegetable oil (rape, castor) are used as base stocks. The application temperature of these grease types are between -35 and +60°C. Good adhesiveness and very good water resistance are the excellent properties. With LIGA CALCIUM-12-HYDROXYSTEARAT drop points of about 130°C are reached, with LIGA CALCIUMSTEARAT 600 and 800 around 100°C, whereas type 600 offers a higher alkalinity for better corrosion protection. By combination with LIGA CALCIUMBEHENAT and -LAURAT grease properties as for example consistency and drop point can be influenced.
LIGA NATRIUMSTEARAT R/D
By using approx. 15% of LIGA NATRIUMSTEARAT R/D in suitable base oils (mineral, vegetable or synthetic; see lithium base grease) sodium base greases of the NLGI-class 2 are produced with drop points between 160 and 180°C. Characteristic features of these lubricants are good adhesive force and the ability to emulsify low quantities of water, which considerably contributes to their especially good corrosion protection. The fulling stability of sodium base rease is moderate. Its temperature application range reaches from -30 to +120°C.
LIGASTAR AL TR
LIGASTAR AL DT
LIGASTAR AL D2
LIGASTAR AL D3
Soaps for the manufacture of aluminium base greases on mineral, vegetable or synthetic basis. LIGASTAR AL TR and DT have low swelling properties and are used for very soft or semiliquid greases with highest softness and transparency (drop point <65°C). The applied quantities are between 4 and 10%.
LIGASTAR AL D2 and D3 produce consistent greases with drop points of about 80°C. The swelling maximum is at product D2. The application quantities are 6-8% for the achievement of NLGI-class 2, depending on the basic oil.
Aluminium based greases are in principal transparent, soft and of good adhesiveness. They have a very good corrosion protection, but are, however, only of moderate water resistance. The lower application temperature is at -30°C. Products on complex soap basis can be used up to approx. +150°C.
Fatty acids as saponification basis
Fatty acids are dissolved in the basic liquid and saponified by adding the hydrous solution of the corresponding hydroxide. Solvent and reaction water are stripped. After that the structure formation of the lubricating grease follows through special reaction control, then mechanical processing. Depending on which grease properties are required, the fatty acids can be used single or in different mixtures. If vegetable oils or synthetic esters are used as base stocks, the saponification phase has to be controlled carefully in order to avoid a possible competitive reaction. When ready-made metal and alkali soaps are used this risk does not exist.
LIGALUB FSO
12-hydroxy stearic acid
LIGACID SG 3
technical stearic acid, Jz max. 3, sack material
LIGACID SG 10-12
technical stearic acid, Jz 10-12, sack material
LIGACID SF 3
technical stearic acid, Jz max. 3, tank truck
LIGACID SF 10-12
technical stearic acid, Jz 10-12, tank truck
Ester oils as base stocks
For the manufacture of fast biodegradable lubricating greases vegetable or synthetic ester oils are used instead of mineral oils. These products show clear advantages regarding lubricity, corrosion protection, viscosity/temperature-behaviour and as mentioned before, biodegradability. However, natural weak points are thermal and hydrolytic stability. In principle it can be said that synthetic esters in this respect and under the aspect of constant quality are definitely superior to vegetable oils. To achieve different product properties all LIGALUB ester oils can be mixed with each other.
LIGALUB 9 GE
Natural castor oil. Applicable as highly viscous basic oil with excellent lubricating properties, alone or mixed with other ester oils. Compared to rapeseed oil it shows clear advantages regarding sludge formation and gumming.
LIGALUB 9 GE-H
Hardened castor oil. As mixing component with increased oxidation stability.
LIGALUB 18 TMP
Trimethylolpropane trioleate. Synthetic ester with good hydrolysis stability. Available also on pure vegetable basis as well as in different viscosity categories.
