Synthetic method of DBM-S (Dibenzoyl Methane-S)

Abstract

The invention discloses a synthetic method of DBM-S (Dibenzoyl Methane-S). The raw materials comprise the following components: xylene, CaCl2, sodium methylate, methyl benzoate and acetophenone in a weight ratio of (220-300) to (28-32) to (20-23) to (54.4-63.1) to 40. The DBM-S is prepared by the following steps: first, injecting xylene in proportion into a container; adding CaCl2 while stirring; then, heating to 135 DEG C to evaporate water; then, cooling to 70 DEG C and adding sodium methylate; after uniformly stirring, heating to 135 DEG C; adding methyl benzoate; after addition, heating to 135 DEG C; dropwise adding acetophenone for 4 hours at constant temperature; after dropwise addition, preserving heat for 1 hours; and carrying out suction filtration, water washing and suction filtration again and drying to obtain a product DBM-S. The synthetic method disclosed by the invention realizes one-step synthesis, so that the conversion ratio reaches up to 86.2%, the synthetic time and steps are shortened and the production cost is lowered, and the synthetic method has remarkable technical and economic advantages.

Description

technical field [0001] The invention relates to a synthesis method of DBM-S, which shortens synthesis time and steps and reduces production cost through a one-step method. Background technique [0002] The β-diketone compound was first introduced into the PVC stabilization system by Akishima Chemical Industry Co., Ltd. of Japan and Rhodia Company of France. It is one of the most effective auxiliary stabilizers so far. It has excellent resistance to initial coloring, especially stable with metal When compounded with other agents, it can significantly improve the initial coloring and color retention of the material. In addition, it can also absorb ultraviolet light above 290nm and has photostabilization effect. [0003] Dibenzoylmethane (DBM) belongs to the diaryl β-diketone in β-diketone compounds. When it is used together with Ca-Zn stabilizer, it has excellent anti-coloring performance, but PVC products have redness in the later stage. The reason for the redness is Becaus...

AI Technical Summary

Problems solved by technology

[0003]Dibenzoylmethane (DBM) belongs to diaryl β-diketones in β-diketone compounds. Excellent, but PVC products have redness in the later stage. The reason for the redness is that the enol structure forms a chelate with iron ions, and the product is red due to the strong light absorption in the wavelength range of 400nm~500nm, which restricts its use. scope

The current synthetic route is: first synthesize DBM through Claisen condensation reaction and then synthesize DBM-S. The method is: xylene is used as a solvent, under the action of sodium methoxide, methyl benzoate is added, stirred and heated, and then styrene is added dropwise Ketone, add dropwise for 4 hours, then acidify for 1 hour, wash with water, wash with alkali, and then wash with water until neutral, crystallize, filter with suction, wash, filter with suction, and dry to obtain DBM; then add the dried DBM to the aqueous solution , Dissolved CaCl2 aqueous solution and NaOH aqueous solution, stir, heat up to 80-85°C, keep warm for 40min, then cool down, filter, wash, and dry. The whole process takes about 13 hours or more, cycle time Longer, high cost, and more sewage generated, so that the price of the finished product is higher; in order to reduce costs and expand the market, the applicant developed a one-step method for direct synthesis through experiments