Modified fumed silica with flattened structure and high tap density as well as preparation method and application of modified fumed silica

A fumed silica and modification technology, applied in chemical instruments and methods, dyed organosilicon compound treatment, inorganic pigment treatment, 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: 2021-07-13
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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  • Modified fumed silica with flattened structure and high tap density as well as preparation method and application of modified fumed silica
  • Modified fumed silica with flattened structure and high tap density as well as preparation method and application of modified fumed silica
  • Modified fumed silica with flattened structure and high tap density as well as preparation method and application of modified fumed silica

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] 1) Preparation of precursor solution

[0042] Add the silicon precursor ethyl orthosilicate and tetramethyldivinyldisilazane to ethanol, and prepare the concentration of orthosilicate to be 0.5wt%, and the concentration of tetramethyldivinyldisilazane to be 5wt % solution and stirred for 20 minutes to fully dissolve the silicon precursor in the solvent.

[0043] 2) Structural 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 is 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 section is 80°C, and the reaction is 3 hours; the heating temperature of the second section i...

Embodiment 2

[0051] 1) Preparation of precursor solution

[0052] Add the silicon precursor tetramethyldivinyldisilazane and tetramethyldivinyldisilazane to ethanol, and the concentration of tetramethyldivinyldisilazane 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) Structural 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 is 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, so that the powder is fully infiltrated;

[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 section is 80°C, and the reaction is 3 hours; the heating temperature o...

Embodiment 3

[0061] 1) Preparation of precursor solution

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

[0063] 2) Structural 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 is added to the rotary vacuum reactor;

[0065] Take 15L of the precursor solution obtained in step 1) and evenly spray it on the above-mentioned fumed silica powder, so that the powder is fully infiltrated;

[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 section is 90°C, and the reaction is for 1 hour; the heating temperature of the second section is 120°C, a...

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Abstract

The invention provides modified fumed silica with a flat structure and high tap density as well as a preparation method and application of the modified fumed silica. By utilizing a rotary vacuum reaction kettle, under the action of a structured modification additive and the gravity action of the fumed silica in the rotary process, the fumed silica is directionally gathered to form a flat structure, so that the tap density of the modified fumed silica is improved, and the fumed silica is endowed with good low-thickening characteristic; the viscosity in a rubber compound of the rubber is reduced; and meanwhile, the porous structure of the fumed silica can be kept, it is ensured that the fumed silica has the high specific surface area, and the high reinforcing characteristic of the fumed silica in rubber is achieved.

Description

technical field [0001] The invention belongs to the technical field of silica modification, and in particular relates to a modified gas-phase silica with a flat structure and high tap density, and a preparation method and application thereof. Background technique [0002] As an important filler additive, fumed silica has a wide range of applications in the fields of rubber, coatings, papermaking, food, feed, and daily chemical products. The tap density of fumed silica is closely related to its dispersibility and rheological properties, especially when it is added to rubber, it 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 adding it to rubber can easily increase the viscosity of the system, resulting in a low amount of fumed silica added to rubber. The method of hydrophobic modification can increase the compatibility of fillers and r...

Claims

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Application Information

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Patent Type & Authority Applications(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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