Method for preparing core-shell silicon dioxide coated nano calcium carbonate

A technology of nano-calcium carbonate and silica, applied in chemical instruments and methods, inorganic pigment treatment, fibrous fillers, etc., can solve problems such as poor dispersion, serious agglomeration, and restricted application fields, and achieve good dispersion and processing performance , good acid resistance and dispersibility, easy for industrial production

Inactive Publication Date: 2008-07-23
上海卓越纳米新材料股份有限公司
View PDF1 Cites 57 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] First, due to the surface characteristics of calcium carbonate, stearic acid treatment is the most effective surface treatment, and the singleness of the surface treatment agent restricts the expansion of the application field;
[0005] The second is that the products treated with stearic acid have poor dispersion and serious agglomeration when used in silicone rubber, and the advantages of nano-powders are not fully utilized;
[0006] The third is due to the fact that calcium carbonate itself will decompose and release carbon dioxide in a slightly acidic medium, which restricts its scope of use.
[0008] Chinese patent, 02115028.1 introduces a preparation method in which sodium silicate is added to calci...

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] In a 30 cubic meter reactor, 25 cubic meters of nano-calcium carbonate slurry (the weight solid content of calcium carbonate is 13.2%, and the average particle diameter of calcium carbonate is 50 nanometers) that has been carbonized to pH equal to 7 is added. Be 300 kilograms of water glass (silica weight content is 25%) of 3.1, under the circulation action of high-shear emulsification pump, control reaction temperature is 30 ℃, feed the kiln gas of carbon dioxide volume content 28% and carry out carbonization to pH It is 6.8. Under the action of carbon dioxide gas, the silicate is hydrolyzed to form silica sol, which is evenly coated on the surface of nano-calcium carbonate, forming a layer of core-shell silicon dioxide coated on nano-calcium carbonate. Add titanate coupling agent TC-311 (35 kg of TC-311 dissolved in 800 kg of water to make a coating agent solution) to the slurry for surface treatment to obtain core-shell silica coated with nano-active carbonic acid Ca...

Embodiment 2

[0030] In the reactor of 30 cubic meters, 25 cubic meters of nano-calcium carbonate slurry (the weight solid content of calcium carbonate slurry is 12.9%, and the average particle diameter of calcium carbonate is 100 nanometers) equal to 7 to PH, add partial Calcium silicate 80 kg, under the circulation of high-shear emulsification pump, the reaction temperature is controlled at 25.0 ° C, and the kiln gas with a carbon dioxide volume content of 29% is introduced for carbonization until the pH is 7.0, and the silicate is under the action of carbon dioxide gas. , hydrolyzed silica sol, and evenly coated on the surface of nano-calcium carbonate, forming a layer of core-shell silica coated on nano-calcium carbonate. Add emulsified stearic acid coating solution (90 kg of stearic acid dissolved in 1500 kg of hot water, and add 80 kg of 40% liquid caustic soda to emulsify and dissolve) in the slurry for surface treatment to obtain the core shell Shaped silicon dioxide is coated on na...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a preparation method for core-shell type silicon dioxide-coated nanometer calcium carbonate, which comprises following steps: adding silicate in calcium carbonate suspension pulp; stirring and mixing using emulsion pump; introducing kiln gas with CO2 for carbonization until the pH is 6.5 to 7.0; heating to 60 to 90 DEG C; adding coating agent for coating treatment; the product is obtained after the coated pulp is filtered and the filter cake is dried. The preparation method for core-shell type silicon dioxide-coated nanometer calcium carbonate has the advantages of improving the acid resistance of nanometer calcium carbonate since silica sol precipitated through hydrolysis is coated on the surface of nanometer calcium carbonate, improving dispersion of the product in polymer due to surface treatment using coupling agent and organic acid, good acid resistance and dispersion, greatly improving physical and chemical properties, and felicitating industrial production with simple operation.

Description

technical field [0001] The invention relates to a preparation method of calcium carbonate, in particular to a preparation method of core-shell silica-coated nano-calcium carbonate. Background technique [0002] As a functional filler, nano-active calcium carbonate is widely used in coatings, rubber, plastics and other industries. Its main purpose is to improve the comprehensive performance of products and reduce production costs. [0003] However, there are many problems in the actual application of nano-active calcium carbonate: [0004] First, due to the surface characteristics of calcium carbonate, stearic acid treatment is the most effective surface treatment, and the singleness of the surface treatment agent restricts the expansion of the application field; [0005] The second is that the products treated with stearic acid have poor dispersion and serious agglomeration when used in silicone rubber, and the advantages of nano-powders are not fully utilized; [0006] Th...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C09C1/02C09C3/06
Inventor 顾达邓丽丽姚成
Owner 上海卓越纳米新材料股份有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap