Preparation method of rare earth heat stabilizer

Abstract

The invention provides a preparation method of a rare earth heat stabilizer. The method comprises the following steps: (1) dissolving lanthanum nitrate and neodymium nitrate into ethanol, preparing a 2.4mol / L rare earth-ethanol solution, controlling the molar ratio of the lanthanum nitrate to the neodymium nitrate to be 0.78: 0.25, transferring the rare earth-ethanol solution into a reaction vessel, and heating up to 75-90 DEG C; (2) preparing a 1.2mol / L sodium hydroxide water solution, dripping the prepared sodium hydroxide water solution into the rare earth-ethanol solution, controlling the molar ratio of hydroxide ions to two rare earth cations to be 3: 1.03, and reacting for 10-20 minutes; (3) adding stearic acid into the reaction vessel for three times, wherein the amount of the stearic acid added for the first time is 50% of the total adding amount, the amount of the stearic acid added for the second time is 30% of the total adding amount, and the amount of the stearic acid added for the third time is 20% of the total amount; controlling the molar ratio of the stearic acid to the rare earth cations to be 3: 1.03, and reacting for 20-30 minutes; and (4) filtering the product, washing with water, drying, crushing and grinding to obtain the powdered stearic acid rare earth heat stabilizer. The method is simple in technology, less in three wastes and high in yield.

Description

technical field [0001] The invention belongs to the field of PVC heat stabilizers and relates to a preparation method of rare earth heat stabilizers. Background technique [0002] Heat stabilizer is one of the necessary additives for PVC processing. It has various varieties and different properties. Rare earth heat stabilizer is a unique PVC heat stabilizer variety in my country. It has the characteristics of high efficiency and non-toxicity, and is a new type of environmental protection. Heat stabilizers. The synthesis techniques of rare earth heat stabilizers mainly include double decomposition method, saponification method and direct melting method. Different methods have their own characteristics. The metathesis method must be carried out under fairly diluted conditions, the reaction speed is slow, the industrial wastewater is more, and the cost is higher; the saponification method requires two-stage alkali addition, the operation is more complicated, and the process con...

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Problems solved by technology

Different methods have their own characteristics. The metathesis method must be carried out under fairly diluted conditions, the reaction speed is slow, the industrial wastewater is more, and the cost is higher; the saponification method requires two-stage alkali addition, the operation is more complicated, and the process control is strict. ; The direct melting method is in the presence of a catalyst, heating and stirring the mixture of fatty acid and rare earth oxides, and one-step synthesis of fatty acid rare earth compounds. The required reagent types are few, and the process and equipment are simple, but the yield is low

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