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HDK® H21

HDK® H21 is a synthetic, hydrophobic, amorphous silica produced via flame hydrolysis. It is a white colloidal powder of high purity. HDK® H21 is used as a thickening and thixotropic agent in various applications such as composites, coatings, adhesives, and sealants, particularly in vinylester, epoxy, and polyurethane systems.

Brand: HDK (36 products)

Chemical Name: Pyrogenic Silica

CAS Number: 112945-52-5

Functions: Rheology Modifier, Thickener, Thixotrope

Chemical Family: Silica

Compatible Polymers & Resins: Epoxies (EP), Polyurethanes (PU), Vinyl Esters

Synonyms: Fumed Silica, Silica, Silicon Dioxide

Technical Data Sheet

Enhanced TDS

Knowde-enriched technical product data sheet

Identification & Functionality

Features & Benefits

CASE Ingredients Features
Materials Features

Applications & Uses

Markets
Applications
Compatible Polymers & Resins
Composites End Use
Applications
  • Adhesives
  • Anti-Corrosive Coatings
  • Composites
  • Do It Yourself
  • Flooring Installation
  • Industrial Coatings
  • Rheology Control
  • Sealants
  • Structural Bonding of Wind Turbines
  • Wind Energy
Application Details

HDK® H21 is applied as a thickening and thixotropic agent in composites, coatings, adhesives and sealants, especially in vinylester, epoxy and polyurethane systems. It is not suitable for pharmaceuticals, food and feed. A good dispersion of HDK® H21 is a must to assure optimum performance.

Properties

Color
Physical Form
Appearance
White colloidal powder
Typical Properties
ValueUnitsTest Method / Conditions
BET Surface (of the hydrophobic silica)approx. 110 m²/gDIN ISO 9277 DIN 66132
Density (at 20°C, SiO₂)approx. 2.2 g/cm³DIN 51757
SiO₂ Content (based on the substance heated at 1000°C for 2 hours)min. 99.8%DIN EN ISO 3262-19
Specifications
ValueUnitsTest Method / Conditions
BET Surface (of the hydrophilic silica)170 - 230 m²/gDIN ISO 9277 DIN 66132
Carbon Content4.8 - 6.4 %DIN ISO 10694
Loss on Drying (at 105°C, 2 hours)max. 0.6 %DIN EN ISO 787-2
pH (in 4% dispersion, 1:1 mixture of water-methanol)4.0 - 7.0-DIN EN ISO 787-9
Sieve Residue (min. 40 µm)max. 0.1 %DIN EN ISO 787-18, Mocker Apparatus
Surface ModificationPolydimethylsiloxy--
Tamped Densityapprox. 50 g/lDIN EN ISO 787-11
Properties

White colloidal powder of high purity.

Regulatory & Compliance

Safety & Health

Safety Notes

During transportation and processing HDK® H21 may cause electrostatic charges. Like other amorphous silicas HDK® H21 does not show either carcinogenic (IARC classification, Volume 68, 1997) or mutagenic properties.

Packaging & Availability

Country Availability
Packaging Type
Regional Availability
  • Africa
  • Asia
  • Europe
  • Latin America
  • North America
  • Oceania
Packaging Information

HDK® H21is offered in following packaging:

  • Pallet with paper bags: 10 kg bags
  • Big bags: 170 kg (big bag on pallet)

Storage & Handling

Storage Information

HDK® H21should be stored in the original packaging in dry storage areas.