Silica For Green Tire

◆Description of products

GS-670 is a hydrophobic fumed silica which is created by subjecting hydrophilic grades with BET of 380m2/g to chemical post-treatment with HMDS (Hexamethyldisilazane).

Hydrophobic fumed silica is made by hydrolyzing exertion chloroethane in oxy-hydrogen flame. From 2008 year till now, we began to produce fumed silica; the annual sales reached 1500 tons. Main used in paint and coating, as additive agent used to prevent subside, thickening, thixotropic agent and prevent sagging in liquid system. There is an effective changing in the aspect of liquid viscosity.

◆Application Scopes

Silicon rubber is ageing-resistant, high and low temperature resistant and electricity-insulated. However, the molecular chain of silicon rubber is soft, the interaction force is weak, so silicon rubber needs to be reinforced before actual usage.

Fume silica is an ideal reinforcing agent for silicon rubber. The strengthening is fundamentally brought about by silanol groups being interacted with or Si-methyl bonds being radically cleaved into the polymer. The surface silanol groups (Si-OH) of fumed silica react with silicone rubber macromolecule ,then generates a silicon rubber molecular adsorption layer on the surface of silica, then a three-dimensional network structure is formed. This structure effectively limits the deformation of the silicone rubber molecular chain, thereby achieving the reinforcing effect.

◆The specification, feature and application

Properties (GS-670)	Unit	Typical Value	Testing Method
Specific Surface Area（BET）	m²/g	380±30	GB/T 20020
PH value in 4% dispersion		5.5～8.0	GB/T 20020
Loss on drying(2 hours at 105℃)	wt%	≤0.5	GB/T 20020
Loss on ignition(2 hours at 1000℃ based on material dried for 2 hours at 105℃)	wt%	≤4.0	GB/T 20020
Silica Content(Based on ignited material)	wt%	≥99.8	GB/T 20020
Tamped Density（Based on material dried at 105℃ for 2 hours）	g/L	40～60	GB/T 20020
Carbon Content (Based on material dried at 105℃ for 2 hours)	wt%	2.5～4.0	GB/T 20020