阅读说明：本技术 一种纳米二氧化钛分散乳液及制作工艺 (Nano titanium dioxide dispersion emulsion and preparation process thereof ) 是由 李浪 胡朝建 张金明 于 2018-08-24 设计创作，主要内容包括：本发明揭示了一种纳米二氧化钛分散乳液及制作工艺。该方法使用聚丙烯酸钠、聚丙烯酸、六偏磷酸钠作为分散剂,合理配比,在高速分散机上预分散后,再通过纳米研磨机上研磨一定时间即可得到稳定的纳米二氧化钛分散乳液。该方法制得的纳米二氧化钛分散液有以下特点：固含量可调、溶液高度稳定、PH中性、分散剂无毒易得、D90粒径低于80nm、光催化效果极佳、极易规模化生产,可用于多种领域。(The invention discloses a nano titanium dioxide dispersion emulsion and a preparation process thereof. The method uses sodium polyacrylate, polyacrylic acid and sodium hexametaphosphate as dispersing agents, the reasonable proportion is adopted, after pre-dispersing on a high-speed dispersing machine, the stable nano titanium dioxide dispersion emulsion can be obtained by grinding for a certain time on a nano grinder. The nano titanium dioxide dispersion liquid prepared by the method has the following characteristics: the solid content is adjustable, the solution is highly stable, the pH is neutral, the dispersing agent is non-toxic and is easy to obtain, the particle size of D90 is less than 80nm, the photocatalysis effect is excellent, the large-scale production is easy to realize, and the method can be used in various fields.)

1. A nano titanium dioxide dispersion emulsion is characterized in that: the nano titanium dioxide emulsion comprises nano titanium dioxide, a dispersing agent and water, wherein the dispersing agent is sodium polyacrylate, polyacrylic acid and sodium hexametaphosphate.

2. The nano titanium dioxide dispersion emulsion according to claim 1, wherein: the molecular weight of the sodium polyacrylate is 2000-5000.

3. The nano titanium dioxide dispersion emulsion according to claim 1, wherein: the mass ratio of the dispersant sodium polyacrylate to the nano titanium dioxide powder is 5-15 percent; the mass ratio of the polyacrylic acid dispersant to the nano titanium dioxide powder is 1 to 5 percent; the mass ratio of the dispersant sodium hexametaphosphate to the nano titanium dioxide powder is 10-25 percent.

4. The nano titanium dioxide dispersion emulsion according to claim 1, wherein: the pH value of the nano titanium dioxide dispersion emulsion is 6-8.

5. A process for preparing nano titanium dioxide dispersion emulsion is characterized by comprising the following steps: dissolving a dispersing agent in water, adding nano titanium dioxide powder, pre-dispersing for 5-15 minutes on a high-speed dispersing machine at a speed of 3000r/min, and then grinding the pre-dispersed dispersion liquid on a nano grinding machine for 4-8 hours to obtain the nano titanium dioxide dispersion emulsion.

6. The process for preparing nano titanium dioxide dispersion emulsion according to claim 5, wherein: the dispersing agent is polyacrylic acid, sodium polyacrylate and sodium hexametaphosphate, and the polyacrylic acid, the sodium polyacrylate and the sodium hexametaphosphate are dissolved in water in sequence.

7. The process for preparing nano titanium dioxide dispersion emulsion according to claim 5, wherein: the rotation speed of the nano grinder is 2000-2500 r/min.

8. The process for preparing nano titanium dioxide dispersion emulsion according to claim 5, wherein: the ground nano titanium dioxide dispersed emulsion can be used for photocatalysis, and the particle size of D90 of the nano titanium dioxide dispersed emulsion is less than 80 nm.

Technical Field

The invention relates to a nano titanium dioxide dispersion emulsion and a preparation process thereof, belonging to the post-treatment technology of nano materials.

Background

The nano titanium dioxide has good light absorption performance and heat conduction performance, strong catalytic performance, strong ultraviolet ray shielding capacity and excellent transparency, and is widely applied to industries such as rubber, paint, cosmetics, photocatalysis and the like. The excellent performance of the nano titanium dioxide depends on the size of the particle size to a great extent, but the common nano titanium dioxide powder sold in the market at present can generate secondary agglomeration, and three reasons for the agglomeration are generally as follows: 1) the surface hydroxyl base layer reduces the electrostatic repulsion action of the surface, generates Van der Waals force and hydrogen bonds, changes the repulsive force of the molecular check into attractive force and causes agglomeration. 2) Chemical reaction between nano powder and evaporation of water along with temperature change easily occurs on the surface to generate bonding aggregates such as oxygen bridge, salt bridge or organic bridge, namely hard aggregates, and the reaction is usually irreversible. 3) And (3) low-temperature sintering of the nano powder: the formation of the agglomerates leads to the loss of the original physical properties and functions of the particles in the final application of the titanium dioxide, when the nano titanium dioxide is used as a photocatalyst in the final application, the agglomerates need to be dispersed again to prepare an aqueous system dispersion liquid, and when the nano titanium dioxide is used as the photocatalyst, the nano titanium dioxide needs to have small particle size and high long-term stability. The conventional wet grinding method can add a high-content dispersing agent, the PH cannot reach neutrality, and the particle size is not small enough. For example, CN201110428768.5 entitled dispersant and Dispersion technology for improving Wet grinding efficiency of titanium dioxide, the dispersant has good dispersion effect of ground product, particle size of the ground product can only reach 0.20-0.23um, high dosage of dispersant, alkaline pH, and limits application range of the dispersion.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a nano titanium dioxide dispersion emulsion and a preparation process thereof.

The purpose of the invention is realized by the following technical scheme: a nano titanium dioxide dispersed emulsion comprises nano titanium dioxide, a dispersing agent and water, wherein the dispersing agent is sodium polyacrylate, polyacrylic acid and sodium hexametaphosphate.

Preferably, the molecular weight of the sodium polyacrylate is 2000-5000.

Preferably, the mass ratio of the dispersant sodium polyacrylate to the nano titanium dioxide powder is 5-15%; the mass ratio of the polyacrylic acid dispersant to the nano titanium dioxide powder is 1 to 5 percent; the mass ratio of the dispersant sodium hexametaphosphate to the nano titanium dioxide powder is 10-25 percent.

Preferably, the pH value of the nano titanium dioxide dispersion emulsion is 6-8.

The invention also discloses a preparation process of the nano titanium dioxide dispersion emulsion, which comprises the steps of dissolving a dispersing agent in water, adding nano titanium dioxide powder, pre-dispersing for 5-15 minutes on a high-speed dispersing machine at the speed of 3000r/min, and grinding the pre-dispersed dispersion liquid on a nano grinding machine for 4-8 hours to obtain the nano titanium dioxide dispersion emulsion.

Preferably, the dispersing agent is polyacrylic acid, sodium polyacrylate and sodium hexametaphosphate, and the polyacrylic acid, the sodium polyacrylate and the sodium hexametaphosphate are dissolved in water in sequence.

Preferably, the rotation speed of the nano grinder is 2000-2500 r/min.

Preferably, the milled nano titanium dioxide dispersion emulsion can be used for photocatalysis, and the particle size of D90 of the nano titanium dioxide dispersion emulsion is less than 80 nm.

The technical scheme of the invention has the advantages that: the invention mainly adopts a method of matching and grinding the wetting dispersant and the high molecular steric hindrance dispersant for dispersion. The wetting dispersant fully wets the nano titanium dioxide powder, reduces the surface tension of the powder, improves the solid-liquid interface compatibility and ensures that the powder obtains better dispersion. The nano-mill is used for high-speed grinding, the penetration effect of the wetting dispersant is increased, the agglomeration is opened more completely, so that small particles are dispersed in a liquid medium, and the steric hindrance dispersant is added to prevent re-agglomeration.

The nano titanium dioxide dispersion emulsion prepared by the method has the advantages of low particle size, small using amount of the dispersing agent, good stability, good photocatalysis effect and convenience for large-scale production.

Detailed Description

The objects, advantages and features of the present invention will be explained by the following non-restrictive description of preferred embodiments thereof. The embodiments are merely exemplary for applying the technical solutions of the present invention, and any technical solution formed by replacing or converting the equivalent thereof falls within the scope of the present invention claimed.

The invention discloses a nano titanium dioxide dispersion emulsion and a preparation process thereof, and particularly relates to a nano titanium dioxide dispersion emulsion which comprises nano titanium dioxide, a dispersing agent and water, wherein the dispersing agent is sodium polyacrylate, polyacrylic acid and sodium hexametaphosphate. The molecular weight of the sodium polyacrylate is 2000-5000. The mass ratio of the dispersant sodium polyacrylate to the nano titanium dioxide powder is 5-15 percent; the mass ratio of the polyacrylic acid dispersant to the nano titanium dioxide powder is 1 to 5 percent; the mass ratio of the dispersant sodium hexametaphosphate to the nano titanium dioxide powder is 10-25 percent, the mass ratio is calculated according to the ratio of the powder to the dispersant, and the balance is water. The pH value of the nano titanium dioxide dispersion emulsion is 6-8.