Composition and Method of Manufacturing Calcium Sulfonate Greases Using Alkali Metal Hydroxide and Delayed Addition of Non-Aqueous Converting Agents

摘要

An overbased calcium sulfonate grease composition and method of manufacture comprising added alkali metal hydroxide alone or in combination with (a) calcium hydroxyapatite and/or added calcium carbonate used as calcium containing bases for reacting with complexing acids) and/or (b) at least one delay period between the addition of water as a converting agent and addition of a portion of a non-aqueous converting agent. A delay period may involve the period of time it takes to adjust the temperature of the mixture, a period of time during which the mixture is held at a temperature or within a range of temperatures, and multiples and any combination thereof. These calcium sulfonate greases have improved thickener yield and high dropping points compared to greases made without added alkali metal hydroxide and delay between the additions of water and a non-aqueous converting agent, particularly when a poor quality overbased calcium sulfonate is used.

主权项

1. A method for making a complex overbased calcium sulfonate grease comprising the steps of:
mixing an amount of overbased oil-soluble calcium sulfonate having amorphous calcium carbonate dispersed therein with a base oil, and one or more converting agents to form a pre-conversion mixture; converting the pre-conversion mixture to a converted mixture by heating until conversion of the amorphous calcium carbonate to crystalline calcium carbonate has occurred; mixing an amount of an alkali metal hydroxide with the pre-conversion mixture, converted mixture or both; and mixing an amount of one or more complexing acids with the pre-conversion mixture or the converted mixture or both; and wherein the amount of overbased oil-soluble calcium sulfonate is around 10% to 45%.