Unlock instant, AI-driven research and patent intelligence for your innovation.

Dispersion of high surface area silica

A dispersion, surface area technology, applied in the direction of silica, silicon oxide, nanotechnology for materials and surface science, which can solve the problem of low cost

Inactive Publication Date: 2012-10-10
EVONIK DEGUSSA GMBH
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] Preparation of stable highly filled dispersions of aggregated silica with high surface area has not been achieved by dispersion techniques that are less costly than the collision method of two predispersion streams

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Dispersion of high surface area silica
  • Dispersion of high surface area silica

Examples

Experimental program
Comparison scheme
Effect test

Embodiment P1

[0046] Potassium-silicon mixed oxide powder P1 (according to German patent application: patent application number 102005027720.9, application date June 16, 2005): evaporate 85kg / h of SiCl 4 , and transfer it to the center tube of a burner of the type described in DE-A-19650500. Additionally, feed 40m into the pipe 3 / h(stp) of hydrogen and 124m 3 / h(stp) of air. The gas mixture exits the inner burner nozzle and burns in the combustion chamber of the water-cooled flame tube. In order to avoid caking situation, feed another 4m 3 / h(stp) of secondary hydrogen into the jacketed nozzle surrounding the central nozzle.

[0047] The aerosol is obtained from a 5% strength potassium chloride aqueous solution through a two-fluid nozzle mounted on the base of the container. Produce 1100g / h aerosol. With the help of 18m 3 / h(stp) carrier gas (air) flow, carrying the aerosol through an externally heated tube, directs the carrier gas so that it first impinges laterally on the tray bas...

Embodiment P2

[0050] Potassium-silicon mixed oxide powder P2 (according to European Patent Application: Patent Application No. 05024753.5, filing date 12.11.2005): evaporated 4.44 kg / h of SiCl 4 . With the help of 3.3m 3 / h(stp) of air is used as carrier gas to transfer the vapors into the mixing chamber. In addition, the 2.3m 3 / h(stp) of core hydrogen and 6.9m 3 / h(stp) of primary air is introduced into the mixing chamber. In the central tube, the reaction mixture is fed to a burner and ignited. The flame burns in a water-cooled combustion tube. Bring in another 20m 3 / h(stp) secondary air to the reaction chamber. At a temperature of 320° C., 191 g / h of a 3.0% by weight aqueous solution of potassium chloride were introduced through nozzles into the flow of silica granules, hydrochloric acid, air and nitrogen. After an average residence time of 12 ms, the temperature of the mixture was raised to 500°C. After an average residence time of 24 s, metal oxide particles were deposited i...

Embodiment D1

[0054] A 100 liter stainless steel batch vessel was charged with 45.0 kg of DI (fully demineralized) water. Then, 30 kg of P1 was sucked in under shear conditions using the suction tube of Ystral Conti-TDS 3 (stator slot: 4 mm ring and 1 mm ring, rotor / stator distance: about 1 mm). After the addition was complete, the suction port was closed, followed by shearing at 3000 rpm for 20 minutes. The heat generated during dispersion operation is removed by an external heat exchanger. Using 20 kg of DI water, the dispersion was diluted and the pH was adjusted from 3.4 to 10.0 with 2.6 kg of aqueous potassium hydroxide (30% strength) under shear. Then, 2.4 kg DI water was added to obtain 30 wt% SiO 2 Content, repeated shearing for about 5 minutes to homogenize.

[0055] The average aggregate diameter was 81 nm (measured with Horiba LA 910) or 47 nm (measured with Zetasizer 2000HS, Malvern).

[0056] Even after 6 months, the dispersion showed no signs of gelling or settling.

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

PropertyMeasurementUnit
particle sizeaaaaaaaaaa
diameteraaaaaaaaaa
Login to View More

Abstract

Dispersion comprising water and mixed potassium silicon oxide powder, wherein the mixed oxide powder is in the form of aggregates of primary particles, has a BET surface area of 100 to 400 m2 / g, has an average aggregate diameter in the dispersion of less than 100 nm, and possesses a potassium fraction of 0.05% to 1.5% by weight, calculated as K2O and based on the mixed oxide powder, and - the dispersion has a fraction of mixed oxide powder in the dispersion of 25% to 40% by weight, the sum of water and mixed oxide powder is at least 98% by weight and the pH is 9 to 11.5.

Description

technical field [0001] The present invention relates to highly filled dispersions comprising high surface area silica and their preparation and use. Background technique [0002] Highly filled silica dispersions are known. They are used, for example, in polishing processes (chemical mechanical polishing), in the paper industry for the production of paper coatings or in the glass industry for the production of glass mouldings. [0003] The fumed silica powder is preferably prepared by flame hydrolysis. In this operation, a silicon compound in vapor form, usually silicon tetrachloride, is combusted together with hydrogen and oxygen. During this operation, in a first step, hydrogen reacts with oxygen to form water, which in a second step hydrolyzes silicon compounds to form fumed silica. [0004] In this operation, first primary particles are formed, which link during a further reaction to form aggregates. Aggregates are fused primary particles. Aggregates can further aggr...

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
Patent Type & Authority Patents(China)
IPC IPC(8): C01B33/18C09D7/61
CPCC01P2006/12C09D5/34C08K3/22C09K3/1003C01P2006/22C01P2004/64C01P2006/19C09D7/1216C01P2004/50C09D7/1266C01B33/1417B82Y30/00C09D7/61C09D7/67
Inventor 不公告发明人
Owner EVONIK DEGUSSA GMBH