阅读说明：本技术 一种改善水滑石初期白度的水热合成方法 (Hydrothermal synthesis method for improving initial whiteness of hydrotalcite ) 是由 张顺华 于 2018-07-17 设计创作，主要内容包括：本发明公开了一种改善水滑石初期白度的水热合成方法,属于水滑石生产技术领域,首先制备溶液甲,然后制备制备溶液乙,再制备溶液丙,最后将上述三溶液按照体积比甲5-10％,乙30-45％,丙40-55％,在旋转液膜反应器中快速混合,混合后得到的浆液在100℃下回流晶化8-10h,干燥后得到初期稳定性好的水滑石粉体,本发明的水热合成方法制得的水滑石粒度分布为15-100nm,可以实现水滑石初期稳定性提高,本发明巧妙的在复合过程中引入新的工艺和材料,实现初期白度提高,钙锌稳定剂品质上升,成本降低,安全高效、产品性能高、降低污染,可以有效解决了水滑石使用过程中前期稳定剂不够、影响PVC制品初期白度的问题。(The invention discloses a hydrothermal synthesis method for improving initial whiteness of hydrotalcite, which belongs to the technical field of hydrotalcite production, and comprises the steps of firstly preparing a solution A, then preparing a solution B, then preparing a solution C, and finally rapidly mixing the three solutions according to the volume ratio of 5-10% of A, 30-45% of B and 40-55% in a rotary liquid membrane reactor, carrying out reflux crystallization on the mixed slurry at 100 ℃ for 8-10h, and drying to obtain hydrotalcite powder with good initial stability, wherein the particle size distribution of the hydrotalcite prepared by the hydrothermal synthesis method is 15-100nm, and the initial stability of the hydrotalcite can be improved. The method can effectively solve the problems that the early-stage stabilizer is insufficient in the use process of the hydrotalcite and influences the initial whiteness of the PVC product.)

1. A hydrothermal synthesis method for improving initial whiteness of hydrotalcite is characterized by comprising the following steps:

the method comprises the following steps: preparation of solution A

Adding 45-60ml of acetylacetone into 8-12g of calcium hydroxide, pouring into a single-neck flask, sealing the flask opening after inserting a stirring paddle, putting the flask into a water bath with the temperature of 80-100 ℃ for heating, starting stirring for 15-20 minutes, and adding water for diluting to 800-1000ml for later use;

step two: preparation of solution B

Magnesium and aluminium salts as Mg²⁺/Al³⁺Preparing a mixed salt solution according to the proportion of 2-5: 1, and enabling Mg to be mixed²⁺The concentration is 0.3-2.0 mol/L;

step three: preparation of solution C

Mixing NaOH or KOH with soluble carbonate n (CO)₃ ^2-)/n(Al³⁺)＝1.8～3.0,n(OH^-)/[n(Mg²⁺)+n(Al^{3 +})]Preparing a mixed solution according to the proportion of 1.6-2.5, wherein the volume of the mixed solution is the same as that of the mixed salt solution;

step four: the three solutions are quickly mixed in a rotary liquid film reactor according to the volume ratio of 5-10% of A, 30-45% of B and 40-55% of C, slurry obtained after mixing is subjected to reflux crystallization at 100 ℃ for 8-10h, and hydrotalcite powder with good initial stability is obtained after drying.

2. The hydrothermal synthesis method for improving initial whiteness of hydrotalcite according to claim 1, wherein the magnesium salt in the second step is one of magnesium sulfate and magnesium nitrate, and the aluminum salt is one of aluminum sulfate and aluminum nitrate.

3. An improved water as claimed in claim 1The hydrothermal synthesis method for initial whiteness of the talc is characterized in that the soluble carbonate in the third step is as follows: na (Na)₂CO₃、K₂CO₃Any of the above.

4. The hydrothermal synthesis method for improving initial whiteness of hydrotalcite according to claim 1, wherein the particle size distribution of hydrotalcite powder prepared in step four is 15-100 nm.

Technical Field

The invention relates to the technical field of hydrotalcite production, in particular to a hydrothermal synthesis method for improving initial whiteness of hydrotalcite.

Background

Generally, the produced hydrotalcite is magnesium-aluminum hydrotalcite, some hydrotalcite is modified by introducing calcium ions and zinc ions, and finally, carbonate, hydroxyl and other compounds are still in the material, so that the hydrotalcite has a certain effect of improving the initial stability of the hydrotalcite, but the hydrotalcite still cannot meet the requirement of actual production.

When the calcium zinc stabilizer is produced, other auxiliary agents are required to be compounded, so that the cost is high, the production process is complicated, errors are easy to occur, and potential safety hazards and environmental protection problems exist. Can not meet the trend of convenient and efficient market, environmental protection and no pollution.

Disclosure of Invention

The invention aims to provide a hydrothermal synthesis method for improving initial whiteness of hydrotalcite, which is safe and efficient, has high product performance and reduces pollution, and can effectively solve the problems that the early-stage stabilizer is insufficient in the use process of the hydrotalcite and influences the initial whiteness of a PVC product so as to solve the problems provided in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

a hydrothermal synthesis method for improving initial whiteness of hydrotalcite comprises the following steps:

the method comprises the following steps: preparation of solution A

Adding 45-60ml of acetylacetone into 8-12g of calcium hydroxide, pouring into a single-neck flask, sealing the flask opening after inserting a stirring paddle, putting the flask into a water bath with the temperature of 80-100 ℃ for heating, starting stirring for 15-20 minutes, and adding water for diluting to 800-1000ml for later use;

step two: preparation of solution B

Magnesium and aluminium salts as Mg²⁺/Al³⁺Preparing a mixed salt solution according to the proportion of 2-5: 1, and enabling Mg to be mixed²⁺The concentration is 0.3-2.0 mol/L;

step three: preparation of solution C

Mixing NaOH or KOH with soluble carbonate n (CO)₃ ^2-)/n(Al³⁺)＝1.8～3.0,n(OH^-)/[n(Mg²⁺)+n(Al³⁺)]Preparing a mixed solution according to the proportion of 1.6-2.5, wherein the volume of the mixed solution is the same as that of the mixed salt solution;

step four: the three solutions are quickly mixed in a rotary liquid film reactor according to the volume ratio of 5-10% of A, 30-45% of B and 40-55% of C, slurry obtained after mixing is subjected to reflux crystallization at 100 ℃ for 8-10h, and hydrotalcite powder with good initial stability is obtained after drying.

Preferably, the magnesium salt in the second step is one of magnesium sulfate and magnesium nitrate, and the aluminum salt is one of aluminum sulfate and aluminum nitrate.

Preferably, the soluble carbonate in step three is: na (Na)₂CO₃、K₂CO₃Any of the above.

Preferably, the particle size distribution of the hydrotalcite powder prepared in the fourth step is 15-100 nm.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a hydrothermal synthesis method for improving initial whiteness of hydrotalcite, which is used for obtaining hydrotalcite with fine granularity, uniform dispersion and good whitening effect, and adopts a hydrothermal synthesis method, firstly, solution A, solution B and solution C are respectively prepared, then, the prepared solution A, solution B and solution C are rapidly mixed in a rotary liquid film reactor according to the ratio of 5-10% of A, 30-45% of B and 40-55% of C, slurry obtained after mixing is refluxed and crystallized for 8-10h at 100 ℃, hydrotalcite powder with good initial stability is obtained after drying, the particle size distribution of the prepared hydrotalcite is 15-100nm, and the initial stability of the hydrotalcite can be improved The product has high performance and reduces pollution, and can effectively solve the problems that the prior stabilizer is insufficient in the using process of the hydrotalcite and influences the initial whiteness of the PVC product.

Detailed Description

The following examples will explain the present invention in detail, however, the present invention is not limited thereto. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.