Calcium stearate production method

Abstract

The invention discloses a calcium stearate production method. The calcium stearate production method is characterized by including steps of firstly, subjecting ammonium stearate and calcium hydroxide to reaction to generate calcium stearate and ammonia water; secondly, when calcium hydroxide turbid liquid is insufficiently added, stearic acid is excessive, subjecting the stearic acid and the ammonia water to reaction to generate the ammonium stearate, and preparing the ammonium stearate required in the first step; and when calcium hydroxide turbid liquid is slightly excessively added, subjecting the ammonium stearate and the calcium hydroxide to reaction and generating calcium stearate and ammonia water, wherein the ammonia water is freed and is decomposed to generate ammonia gas on the condition of the pH (potential of hydrogen) value of 9-9.5 of the reaction system at the temperature of 65-85 DEG C, and filtrate is composed of water and precious little calcium hydroxide soluble in water. The calcium stearate production method is simple in process and is low in reaction temperature and energy consumption and low in requirements for equipment as compared with a double decomposition process, no reflux reaction is needed in the later stage of reaction, even general double decomposition process production equipment can produce products, economic benefits are evident, and accordingly, the calcium stearate production method is applicable to further popularization.

Description

technical field [0001] The invention belongs to the technical preparation field of heat stabilizers, and in particular relates to a new process for synthesizing aqueous phase calcium stearate. Background technique [0002] Calcium stearate is a non-toxic heat stabilizer for polyvinyl chloride and an indispensable processing aid in the processing of polyvinyl chloride resin plastics. At present, the domestic production of calcium stearate is mainly based on the double decomposition method, that is, stearic acid reacts with sodium hydroxide solution in the water phase to form a sodium stearate soap solution, and the sodium stearate soap solution is combined with a pre-prepared water-soluble calcium salt. reaction to generate calcium stearate and water-soluble sodium salts, the hot water containing water-soluble inorganic salts produced during the production process cannot be recycled, and thus, a large amount of waste water containing inorganic salts can only be discharged (if...

AI Technical Summary

Problems solved by technology

At present, the domestic production of calcium stearate is mainly based on the double decomposition method, that is, stearic acid reacts with sodium hydroxide solution in the water phase to form a sodium stearate soap solution, and the sodium stearate soap solution is combined with a pre-prepared water-soluble calcium salt. reaction to generate calcium stearate and water-soluble sodium salts, the hot water containing water-soluble inorganic salts produced during the production process cannot be recycled, and thus, a large amount of waste water containing inorganic salts can only be discharged (if the inorganic salts are recovered, it can be Consumption is too high, no economic value)

[0003] Stearic acid and calcium hydroxide are mixed evenly in the water phase at low temperature and heated slowly, and the heavy product with coarse particles is obtained from the reaction, which is easy to form a package and the reaction is not complete. Additional crushing equipment is required to meet the user's fineness requirements

[0004] Another kind of calcium stearate is produced by melting method. Although there is no waste water discharge, due to the high viscosity of calcium stearate melt, the requirements for equipment are very high, and the processing cost is high. There are few domestic manufacturers of calcium stearate. Using the fusion process

[0005] There is also a "method for synthesizing calcium stearate in one step without discharge" without the right of patent of the publication number CN101117312A. Although it is explained that there is no discharge, the latter stage of the reaction still needs to be adjusted with calcium chloride, which will cause more and more chloride ions to accumulate, and still need discharge, and in the later stage of the reaction, reflux reaction at 90~100°C is required. The reflux reaction requires a closed pressure vessel, which requires high equipment and is inconvenient to operate.