Production method of carbamido thickening agent for lubricating grease

Abstract

The invention relates to a method for producing a thickening agent for carbamido lubricating grease. The proposal comprises the following steps: sweeping a dissolving tank and a reactor used in the method by using nitrogen gas; adding a solvent to an ester dissolving tank metrically, then adding isocyanate to the ester dissolving tank metrically, and stirring, heating and dissolving the isocyanate; adding the solvent to an amine dissolving tank metrically, then adding an organic amine to the anime dissolving tank metrically, and stirring, heating and dissolving the organic amine; adding the amine solution and the isocyanate solution to a reactor, mixing and heating the solutions to finish the mixing within 0.5 to 2 hours, and continuing to perform balanced reaction and dispersion for 0.5 to 2 hours at a temperature of between 50 and 100 DEG C; vacuumizing the reactor, and condensing the reactor to reclaim the solvent; and introducing overheated water vapor to the reactor from the bottom thereof for 5 to 30 minutes, and cooling the temperature to below 80 DEG C to obtain the carbamido thickening agent. The method provides a nontoxic, harmless, environment-friendly and safe intermediate raw material which is convenient to transport and store for the production of carbamido lubricating oil, reduces the threshold and the cost for the production of the carbamido lubricating grease, and provides a material foundation for stabilizing and improving the quality of the caramido lubricating grease, and upgrading the import of the lubricating grease varieties.

Description

Technical field [0001] The invention relates to the field of preparation methods for intermediate raw materials of chemical products, in particular to a method for producing thickeners (including diurea, triurea, tetraurea and polyurea) used in urea-based grease. Background technique [0002] Urea-based grease has excellent high temperature performance, water resistance and acid resistance, and has the characteristics of moderate cost and long service life. It has been widely used in harsh and demanding fields such as metallurgy and chemical engineering. The proportion is increasing year by year. According to statistics from the American Lubricating Grease Association (NLGI), in 2006, China's grease output reached 279,000 tons, of which urea-based grease accounted for 3%, the United States accounted for 6%, and Japan as much as 23%. In 2008, the domestic urea-based grease is estimated to be about 10,000 tons. Based on 10% of the soap amount, it is estimated that 1,000 tons of ure...

AI Technical Summary

Problems solved by technology

[0004] Since isocyanates and some amines are highly toxic and / or volatile and / or corrosive, there are several problems in the production of urea-based grease by the above process: 1. Health and safety of workers

The current situation is that most urea-based grease manufacturers have not paid attention to this. In order to avoid the poisoning of harmful substances, workers often ignore the requirements of the production process for feeding speed, timing and quantity, and put it into the reactor early for convenience. It also leads to the problem that the product quality cannot be guaranteed

2. Most of isocyanates and amines are dangerous chemicals, and their transportation and storage are strictly controlled by relevant national laws and regulations, which will inevitably increase the transportation cost of these raw materials, and even affect the timeliness of the supply of these raw materials, especially the distance from the raw material origin Grease manufacturers farther away will have a more significant impact; in addition, isocyanate will self-polymerize and amine will volatilize, which requires high storage conditions, requires low-temperature storage, and storage time is also limited, otherwise the effective content will be affected, thereby reducing its use effect; Transportation, use and storage should also consider possible leakage to the environment

Based on the above reasons, using the traditional production process, the production threshold of urea-based grease is relatively high. If the production output does not reach a large scale, the cost of environmental protection and safety will be high, and at the same time affect the stability and improvement of product quality, and even affect the timely supply of products

Due to the small scale of a large number of domestic lubricating grease production enterprises, the state's control of dangerous goods and the increasing requirements for environmental protection also limit the production of urea-based lubricating grease for such enterprises

3. Due to the high melting point of some isocyanates and amines (such as benzidine), they are not well soluble in conventional mineral base oils, so they cannot be produced by the traditional urea-based grease production process, and the use of appropriate solvents can be used at a lower The temperature dissolves the reactants to produce a urea-based thickener

However, there is a problem that it cannot be filtered in practical applications. The conventional drying process will cause a large amount of organic solvents to be discharged, causing environmental pollution and waste.

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