CN1215127C

CN1215127C - Micro-size silica powder preparation

Info

Publication number: CN1215127C
Application number: CN 02118210
Authority: CN
Inventors: 章浩龙
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-08-19
Filing date: 2002-04-25
Publication date: 2005-08-17
Anticipated expiration: 2022-04-25
Also published as: CN1407026A

Abstract

The present invention discloses a production process for preparing superfine silicon dioxide powder by using silicasol as raw materials. Proper silicasol raw materials are directly made into silicon dioxide powder with the similar grain size to silicasol grains through coagulating and drying. The present invention can be used for preparing the silicon dioxide powder with different grain sizes through selecting the silicasol raw materials with different silicasol grain sizes, the obtained silicon dioxide powder has the grain size range between 5 and 100 nm, particularly between 5 nm and 20 nm, and the silicon dioxide powder prepared by the method of the present invention has the advantages of high powder, uniform grain sizes, simple production process and low production cost, and has high practicability.

Description

The preparation method of micro-size silica powder

Technical field

The present invention relates to a kind of production method of micro-size silica powder, more particularly, be a kind of method for preparing nano silica powder by silicon sol.

Background technology

Superfine silicon dioxide is a kind of submicron or nano level silicon-dioxide powdery, and its primary partical size is below 1 μ m, and generally at 5-100nm, minimum can be controlled in the 5nm-20nm scope.Silanol base and residual oxygen base are rich in its surface, and its performance is different from general trickle silicon-dioxide powdery, can be widely used in the industries such as coating, resin, plastics, electronics, pottery.

The present method of making micro-size silica powder has a variety of, relatively is typically tetraethyl silicate (ETOS) sol-gel method.Patent as applications such as the Zhang Lide of solid-state physics institute of the disclosed Chinese Academy of Sciences in 1996 of Patent Office of the People's Republic of China, publication number is: 1117022A, " a kind of preparation method of silicon dioxide powder with controllable nanon size ", it is raw material that this patent adopts ETOS, by hydrolysis generate silica dioxide gel again the drying pyroprocessing make the nano level superfine silicon-dioxide powdery.Its shortcoming is that the raw silicon acetoacetic ester that adopted costs an arm and a leg and causes the products made thereby cost higher.

And adopt silicon sol is the patent US5352645 (1994) that U.S. E.I.du Pont deNemours and Company is arranged " Silica microspheres; method of improving attrition resistance and use (the silicon dioxide microsphere body improves the methods and applications of wear resistance) " of raw material production superfine silicon dioxide.It is raw material that this patent adopts silicon sol, adds additive such as ammonium citrate or urea etc., by spraying drying, method for calcinating, can prepare the high spraying silicon dioxide microsphere of abrasion resistance.Its shortcoming is the particle diameter of the particle diameter of the silicon-dioxide powdery that makes the in this way little drop of silicon sol during corresponding to spraying, and its diameter is 1 μ m-5 μ m, and can not reach the requirement of nano level product near the particle diameter of silicon sol micelle.

To adopt silicate in addition be raw material, produce superfine silicon dioxide by methods such as chemical precipitation method, carburizing reagent method, inverse micellar solution methods, but these methods exists all manufacturing process loaded down with trivial details, the not high defective of resultant purity.

Summary of the invention

The objective of the invention is to, overcome existing preparation technology's deficiency, adopt cost of material lower, the simple method of production technique can obtain the silicon-dioxide powdery close with the silicon sol particle size analysis, and particle diameter is even, purity is high, be easy to large-scale production.

It is 25 ± 1% that the present invention adopts with dioxide-containing silica, and particle size analysis is that the silicon sol of 5-20nm is a raw material, is jelling agent with ethanol or methyl alcohol, directly makes nano silica powder by gelling, drying.

The advantage that adopts the inventive method to prepare nano silica powder is: the one, and cost of material is cheap, greatly reduces production cost of products, and the silicon sol price is about 1/5th of tetraethyl silicate price on year-on-year basis; The 2nd, the product purity height, and can be according to raw silicon colloidal sol size control micro-size silica powder diameter, superfine silicon dioxide narrow diameter distribution; The 3rd, present method is easy to large-scale production.

Embodiment

Embodiment one:

Select commercial silicon sol for use, reach the AS-25 of chemical industry company limited silicon sol as Shangyu, Zhejiang Province city space, this silicon sol dioxide-containing silica is 25 ± 1%, and particle size analysis is 5-20nm, and its product purity is higher.

Getting particle diameter is 8nm left and right sides silicon sol 50g, under agitation condition, slowly drip 95% ethanol, make progressively dehydrating gel of silicon sol micelle, to abundant gel,, remove major part and contain aqueous ethanolic solution through natural subsidence or filter method, obtain transparent wet gel, put into 200 ℃ of baking oven bakings 6 hours, treat can obtain the about 12g of lily micro-size silica powder behind the naturally cooling, its diameter of particle size is about 9nm.

Embodiment two:

Getting particle diameter is 8nm left and right sides AS-25 silicon sol 50g, under agitation condition, slowly drip methyl alcohol, make progressively dehydrating gel of silicon sol, to abundant gel, remove major part earlier through natural subsidence or filter method and contain methanol aqueous solution, again wet gel is put into 200 ℃ of baking oven bakings 6 hours, treat can obtain the about 12g of lily micro-size silica powder behind the naturally cooling, its diameter of particle size is about 9nm.

In addition, for improving the purity of superfine silicon dioxide, after wet gel is put into baking oven baking again the oven dry thing 800 ℃-1000 ℃ calcinings 1-3 hour, to remove remaining moisture content and other impurity, treat can obtain behind the naturally cooling micro-size silica powder of high purity white.

Certainly,,, can select the silicon sol of different colloidal particle sizes for use, and ethanol or methyl alcohol after filtering are all recyclable according to the particle diameter requirement of required silicon-dioxide powdery according to the method for embodiment one or embodiment two.

The method technology that the present invention produces micro-size silica powder is simple, process is easy to control, can select for use the chemical industry conventional equipment can realize large-scale commercial production, and the primary particle diameter of its silicon-dioxide powdery is close with the silicon sol particle diameter, the silicon-dioxide powdery purity height that makes, particle diameter is even.

Claims

1, a kind of preparation method of nano silicon dioxide, be 25 ± 1% wherein with dioxide-containing silica, particle size analysis is that the silicon sol of 5-20nm is a raw material, it is characterized in that its technology is jelling agent with ethanol or methyl alcohol, directly makes nano silica powder by gelling, drying.