Method for preparing sustained-release coating material with organic silicon

Abstract

The invention discloses a method for preparing a sustained-release coating material with organic silicon. The method comprises the following steps: 1) dissolving a hydrolysate with sodium carboxymethylcellulose and styrene-vinyl acetate-vinyl silane terpolymer according to the mass ratio of (1-100):1 in water; 2) dissolving gelatin in water, adding into the solution of step 1), wherein the mass ratio of gelatin to the sodium carboxymethylcellulose is (0.5-20):1, adding 1-25% of the total mass of a non-ionic emulsion, stirring and dispersing to obtain an O / W type emulsion; and 3) adding a cross-linking agent, continuously stirring and dispersing, subsequently adding acid or acid and water to adjust the pH value to obtain the sustained-release coating material with organic silicon. The material brings into play the characteristics that the organic silicon is low in surface tension and high in chemical stability, enables a coated layer to be dense, improves the sustained-release effect and reduces the number of bubbles generated in the surface in coating, the prepared coating material is applicable to surface coating on variable fertilizer grains and simple and convenient to operate, the process time is shortened, and the production efficiency is improved.

Description

[0001] technical field [0002] The invention relates to a preparation method of a slow-release coating material containing organic silicon, belonging to the technical field of non-metallic materials. Background technique [0003] The loss and invalid utilization of fertilizers have brought huge economic losses and environmental pollution to the society. However, my country is a large agricultural country, and its fertilizer consumption ranks first in the world, and the utilization rate of fertilizers is low in the current season. Therefore, how to improve the utilization rate of fertilizers and organically combine the application of fertilizers with the quality, yield and environmental protection of agricultural products has become one of the hot issues in the field of fertilizer research. [0004] Slow-release fertilizer means that the nutrient release rate can match the law of crop fertilizer demand, and has a specific temperature release rate change rule, in which n...

AI Technical Summary

Problems solved by technology

At present, chemically synthesized slow-release fertilizers represented by urea-formaldehyde are currently the most mature and widely available slow-release fertilizers. Adding urease inhibitors or nitrification inhibitors to steady-state fertilizers can improve the utilization rate of fertilizers. Still can’t prevent the loss of fertilizer; the amount of sulfur used in the sulfur-coated urea process is relatively large, the internal nutrients are not easy to overflow, and the coating layer is easy to oxidize and break, and long-term use will cause acidification of the soil; inorganic mineral salt-coated slow-release control fertilizer Its coating has poor sealability, is easy to detach, and nutrients are easy to dissolve quickly; organic polymer coatings have very good slow-release properties. At present, domestic research on slow-release fertilizers is mainly concentrated on coating materials. Li Dongpo, Shenyang Institute of Applied Ecology, Chinese Academy of Sciences et al. used self-made acetate starch as the main material to develop a film solution for fertilizer coating, and prepared coated urea; Yao Junjie, Department of Chemical Engineering, Tsinghua University, etc. used polymer emulsion as a coating agent to prepare slow-release urea; Chinese patent CN101200393A (a A film material for producing coated fertilizer and its preparation process) reported that starch is used as raw material to modify starch to prepare the film material required for coated fertilizer; CN102786355A provides an environmentally friendly, non-toxic slow-release degradable package Preparation method of membrane material; CN101759496A provides a kind of degradable polymer coating control fertilizer which can improve fertilizer utilization rate and protect agricultural ecological environment; CN101973808A provides a low-cost, degradable natural polymer Materials - Starch as the coating material and the coated slow-release fertilizer using the coating material

In the above-mentioned Chinese patent literature reports, a large number of air bubbles are likely to be generated during the preparation of the coating material, which not only increases the difficulty of operation, but also prolongs the time of the process and reduces the production efficiency. More importantly, when coating fertilizer particles It will form tiny air bubbles on the surface of fertilizer particles, and when the air bubbles are broken, tiny voids will be formed, which will affect the slow-release effect of the coated fertilizer

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