Silica
AssigneeDegussa AG
InventorsJürgen Meyer, Stephanie Frahn, Manfred Ettlinger
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Abstract
Silanized, structurally modified, pyrogenically produced silicas, characterised by groups fixed to the surface, wherein the groups are dimethylsilyl and/or monomethylsilyl, are produced in that pyrogenically produced silica is treated by a known method with dimethyldichlorosilane and/or monomethyltrichlorosilane, the groups dimethylsilyl and/or monomethylsilyl being fixed on the surface of the pyrogenic silica, and is then structurally modified and optionally post-ground. They are used to improve scratch resistance in lacquers.
Claims13
Silanised, structurally modified, pyrogenically produced silicas, characterised by groups fixed to the surface, wherein the groups are dimethylsilyl and/or monomethylsilyl, said silicas having a tamped density of 280 g/l or less, said silicas having been structurally modified by being ball milled and being characterised by the following physico-chemical characteristics:
- BET surface area m2/g:
- 25-400
- Average size of the primary particles nm:
- 5-50
- pH value:
- 3-10
- Carbon content %:
- 0.1-10
- DBP value %:
- <200.
A silanised, structurally modified, pyrogenically produced and ball milled silica having groups fixed to the surface wherein said groups comprise at least one of dimethylsilyl and monomethylsilyl and wherein said silica has a tamped density of 280 g/l or less, said silica having the following physical chemical properties:
- BET surface area m2/g:
- 25-400
- Average size of the primary particles nm:
- 5-50
- pH value:
- 3-10
- Carbon content %:
- 0.1-10
- DBP value %:
- <200.
A lacquer comprising a polyurethane and a silanised silica having been structurally modified by being ball milled and being characterised by the following physico-chemical characteristics:
- BET surface area m2/g:
- 25-400
- Average size of the primary particles nm:
- 5-50
- pH value:
- 3-10
- Carbon content %:
- 0.1-10
- DBP value %:
- <200.
- said silica having a tamped density of 285 g/l or less.
Dependencies are inferred from the claim text.