Method for preparing particle type coating sodium percarbonate

Abstract

The invention discloses a preparation method of granular film coated sodium percarbonate, which solves the problem of the quite low stability of the prior products. In the invention, hydrogen peroxide and sodium carbonate are used as raw materials, an appropriate stabilizer and process parameters are selected to synthesize the granular type film coated sodium percarbonate product, and the raw materials are treated by the steps of dissolution, reaction, centrifugation, fluid bed spray liquid pocket, drying, etc. to prepare the high-stability granular type film coated sodium percarbonate; the bulk density of the granular type film coated sodium percarbonate prepared by the method of the invention is 750 to 1150kg / m3, the grain size is 0.8 to 1.4mm, the content of reactive oxygen species is 13.1 percent to 13.6 percent; the moisture stability is higher than 70 percent and the thermal stability is higher than 90 percent; the product is widely applicable in daily chemical, organic synthesis and other industrial fields.

Description

technical field [0001] The invention relates to the field of fine chemical industry, in particular to a preparation method and wet coating technology of high-stability granular film-coated sodium percarbonate. Background technique [0002] Sodium percarbonate, also known as sodium percarbonate, has the general chemical formula 2Na 2 CO 3 ·3H 2 o 2 , the relative molecular mass is 314.0, and the theoretical active oxygen content is 15.28%. Coated sodium percarbonate (coated sodium percarbonate) is based on granular sodium percarbonate, and a layer of stabilizer is wrapped on the outside to improve product stability. [0003] In addition to being used as a strong oxidant, sodium percarbonate is also widely used in washing, textile, medical treatment, papermaking, electroplating, etc. Because of its high active oxygen content, sodium percarbonate is often used as a bleaching agent, bactericide, disinfectant and food preservation agent etc. Utilizing the characteristic tha...

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Problems solved by technology

[0006] Sodium percarbonate is unstable in a humid environment, and it is easy to decompose and release active oxygen. In order to improve the storage time of the product and expand the use of the product, it is necessary to prepare a percarbonate with good stability, active oxygen content and solubility and other indicators that meet user requirements. For sodium carbonate products, researchers from various countries have carried out a lot of research and exploration from various aspects such as synthesis process, reaction conditions, and stabilizer selection, and have achieved certain results. But so far, how to further improve the stability of sodium percarbonate still remains It is the biggest problem faced by scientific and technological personnel at home and abroad

[0007] ZL93115283.6 (notification number CN1031254C) discloses a kind of method of stabilizing sodium percarbonate, what this method obtains is powdery sodium percarbonate, and stability is relatively poor, and the reaction time in the method is too long, and hydrogen peroxide concentration is low, industrial The application value is not high

[0008] CN1435449A discloses a method for improving storage stability. In the method, an aqueous stabilizer solution is sprayed into a vibrating fluidized bed in stages. The process is cumbersome, and according to the patent specification, it is not clear whether the product stability is wet stability or thermal stability. indicators, and in the detergent industry, the stability under high humidity conditions is more important than thermal stability

[0016] Combining domestic and foreign published literature and invention patents and sodium percarbonate products sold on the market, it can be learned that because sodium percarbonate has high low-temperature activity and fast dissolution rate, if sodium percarbonate with a moisture stability higher than 70% can be prepared , just can replace the sodium perborate originally used in the detergent, but in the production method of the stable sodium percarbonate of large-scale industrial production at present, the production cost is often higher, and the technology is also more complicated, and the overborate with wet stability higher than 70% Sodium carbonate products are difficult to obtain in the market