A kind of high tap density modified fumed silica with flat structure and its preparation method and application

A fumed silica, modified technology, applied in chemical instruments and methods, dyed organosilicon compound treatment, fibrous fillers, etc., can solve the problems of low fumed silica addition, low tap density, particle agglomeration, etc. , to achieve the effect of improving mechanical properties and processing performance, high processing accuracy requirements, and good material fluidity

Active Publication Date: 2022-06-14
TECHNICAL INST OF PHYSICS & CHEMISTRY - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the tap density of conventional fumed silica is low, and it is easy to cause dust to fly during operation, and it is easy to increase the viscosity of the system when added to rubber, resulting in a low amount of fumed silica added to rubber.
The method of hydrophobic modification can increase the compatibility of fillers and rubber, and improve the dispersion of fillers to a certain extent, but it still cannot fundamentally solve the problems of high addition amount and lower system viscosity
[0004] Some modification methods reported at home and abroad can improve the tap density of fumed silica to a certain extent, but due to the limitation of the method, high tap density and precise control of tap density are still not possible
Moreover, the existing tap density improvement and hydrophobic modification are usually implemented in two steps. When the tap density is increased, the particles are often agglomerated, which makes the hydrophobic modification and dispersion of fumed silica poor, and the surface modification Sexual groups are also difficult to control
[0005] In addition, the tap density of fumed silica can also be increased by physical compression, and some hydrophobic modification can also appropriately increase the tap density of fumed silica, but these methods only increase the bulk density of particles. There is no change in the aggregate structure, and the viscosity of the system cannot be reduced after being added to the filler

Method used

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  • A kind of high tap density modified fumed silica with flat structure and its preparation method and application
  • A kind of high tap density modified fumed silica with flat structure and its preparation method and application
  • A kind of high tap density modified fumed silica with flat structure and its preparation method and application

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] 1) Prepare the precursor solution

[0042] The silicon precursors, ethyl orthosilicate and tetramethyldivinyldisilazane, are added to ethanol, and the concentration of ethyl orthosilicate is 0.5wt% and the concentration of tetramethyldivinyldisilazane is 5wt%. % solution, and stirred for 20 minutes to fully dissolve the silicon precursor in the solvent.

[0043] 2) Structure flattening modification

[0044] The tap density of weighing 1kg is 55g / L, and the specific surface area is 205m 2 / g of fumed silica powder, which was added to the rotary vacuum reactor;

[0045] Take 12L of the precursor solution obtained in step 1) and evenly spray it on the above-mentioned fumed silica powder to fully infiltrate the powder;

[0046] Turn on the rotary vacuum reactor, turn on the rotation, turn on the vacuum pump, and turn on the heating;

[0047] The heating temperature of the first stage was 80°C, and the reaction was performed for 3 hours, the heating temperature of the se...

Embodiment 2

[0051] 1) Prepare the precursor solution

[0052] The silicon precursor ethyl orthosilicate and tetramethyldivinyldisilazane are added to ethanol, and the concentration of ethyl orthosilicate is 1wt% and the concentration of tetramethyldivinyldisilazane is 10wt%. The solution was stirred for 20 minutes to fully dissolve the silicon precursor in the solvent.

[0053] 2) Structure flattening modification

[0054] The tap density of weighing 1kg is 50g / L, and the specific surface area is 300m 2 / g of fumed silica powder, which was added to the rotary vacuum reactor;

[0055] Take 10L of the precursor solution obtained in step 1) and evenly spray it on the above-mentioned fumed silica powder to fully infiltrate the powder;

[0056] Turn on the rotary vacuum reactor, turn on the rotation, turn on the vacuum pump, and turn on the heating;

[0057] The heating temperature of the first stage was 80°C, and the reaction was performed for 3 hours, the heating temperature of the secon...

Embodiment 3

[0061] 1) Prepare the precursor solution

[0062] The silicon precursor sodium silicate and hexamethyldisilazane were added to ethanol to prepare a solution with a sodium silicate concentration of 20 wt% and a hexamethyldisilazane concentration of 8 wt%, and stirred for 30 minutes to make the silicon The precursor is fully soluble in the solvent.

[0063] 2) Structure flattening modification

[0064] The tap density of weighing 1kg is 60g / L, and the specific surface area is 300m 2 / g of fumed silica powder, which was added to the rotary vacuum reactor;

[0065] Get 15L of the precursor solution obtained in step 1) and evenly spray it on the above-mentioned fumed silica powder to fully infiltrate the powder;

[0066] Turn on the rotary vacuum reactor, turn on the rotation, turn on the vacuum pump, and turn on the heating;

[0067] The heating temperature of the first stage is 90°C, and the reaction is performed for 1 hour. The heating temperature of the second stage is 120°...

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Abstract

The invention provides a high tap density modified fumed silica with a flattened structure, a preparation method and application thereof. The present invention utilizes a rotary vacuum reactor, under the action of structural modification additives, and utilizes the self-gravity of gas-phase silica during the rotation process, so that the gas-phase silica is oriented and aggregated to form a flat structure, which improves the efficiency of the modified gas phase. The tap density of silica endows fumed silica with good low-thickening properties and reduces the viscosity of its mixed rubber with rubber; at the same time, the present invention can maintain the porous structure of fumed silica and ensure that fumed silica With a high specific surface area, it realizes the high reinforcing properties of fumed silica in rubber.

Description

technical field [0001] The invention belongs to the technical field of silica modification, and in particular relates to a modified fumed silica with a flattened structure and high tap density, and a preparation method and application thereof. Background technique [0002] As an important filler auxiliary, fumed silica has a wide range of applications in the fields of rubber, paint, paper, food, feed and daily chemical products. The tap density of fumed silica is closely related to its dispersibility and rheological properties, especially its addition to rubber has an important influence on the processing performance. [0003] At present, the tap density of conventional fumed silica is low, and it is easy to cause dust to fly during operation, and it is easy to increase the viscosity of the system when added to rubber, resulting in a low addition amount of fumed silica in rubber. The compatibility of fillers and rubbers can be increased by hydrophobic modification, and the ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09C1/30C09C3/04C09C3/12C08K9/06C08K7/26C08L83/04
CPCC09C1/3009C09C1/3081C09C1/309C09C3/006C09C3/04C09C3/12C08K9/06C08K7/26C01P2006/12C01P2006/11C01P2004/04C08K2201/005C08K2201/004C08K2201/006C08L83/04
Inventor 谭龙飞孟宪伟吴琼任湘菱付长慧
Owner TECHNICAL INST OF PHYSICS & CHEMISTRY - CHINESE ACAD OF SCI
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