Synthetic process for DOTP-1

Abstract

The invention discloses a synthetic process for DOTP-1. The synthetic process comprises the following steps: (1) taking raw materials at the molar ratio of terephthalic acid: heptyl alcohol=1:(2.7-2.9), and taking 3.3% of the total mass of phthalic acid and heptyl alcohol of a titanium(IV) isopropoxide catalyst; (2) putting all terephthalic acid and one third of the heptyl alcohol into a reaction kettle, heating up to 150-180 DEG C, adding 50% of the total quantity of the catalyst, and adding the catalyst within 4-6 minutes; (3) heating a reaction liquid I obtained in step (2) up to 190-210 DEG C, adding one third of the heptyl alcohol, and adding 25% of the catalyst after 5-10 minutes; (4) conducting heat preservation on a reaction liquid II obtained in step (3), adding surplus heptyl alcohol and catalyst into the reaction liquid II for reacting to obtain a crude product; (5) conducting water washing, dealcoholization, decoloring and filtering on the crude product to obtain a finished product. According to the synthetic process, the reaction time is greatly shortened and the reaction temperature is greatly lowered, so that the product quality is guaranteed and the product grade and yield are also improved, and the energy consumption and manufacturing cost are lowered.

Description

technical field [0001] The invention belongs to the synthetic technique of plasticizer, more specifically relate to a kind of synthetic technique of terephthalate (2-propylheptyl) ester plasticizer. Background technique: [0002] Di(2-propylheptyl) terephthalate (DOTP-1) is an industrial plasticizer with good cold resistance, heat resistance and extraction resistance. DOTP-1 has excellent electrical properties and high plasticizing efficiency. It is suitable for industrial processing of polyvinyl chloride resin, especially for heat-resistant cable materials, such as cable materials requiring high insulation, transparent plastic particles, and light box films. [0003] Terephthalic acid and excess heptanol undergo an esterification reaction in the presence of a catalyst to generate bis (2-propylheptyl) terephthalate and water, which are separated and separated by a water separator, and then decompressed and stripped. Reach the flash point index, filter, measure, and package ...

AI Technical Summary

Problems solved by technology

The normal reaction time in the existing production process is 10-12 hours, but the long-term high-temperature reaction is prone to oxidation, which affects the product grade and yield