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US 12,427,444 B2Granted
Defoamer active, manufacturing thereof, and deforming formulation
AssigneeW.R. Grace & Co.-Conn.
InventorFeng Gu
Life of this patent
Estimating the term…
Abstract
This invention relates to a defoamer active. The defoamer active may include hydrophobized silica particles obtained by treating silica particles with a hydrophobilizing agent. The silica particles may have a BET surface of less than about 150 m2/g, a surface pH of at least about 10, and a median particle size ranging from about 2 μm to about 50 μm. The carbon content of the hydrophobized silica particles may not be more than 3%.
Claims15
A defoamer active, comprising:
- hydrophobized silica particles having a carbon content of not more than 3.0%, wherein the hydrophobized particles comprise silica particles having a BET surface area of less than about 60 m2/g, a surface pH of at least about 10, a pore volume of about 0.25 cc/g or less, and a median particle size ranging from about 2 μm to about 50 μm,
- wherein the hydrophobized silica particles comprise a hydrophobilizing agent covalently bonded to the surface thereof in an amount of not more than 6% by weight based on a total weight of the hydrophobized silica particles, and
- wherein the hydrophobilizing agent is a silanol terminated polydimethylsiloxane having a content of hydroxyl group ranging from about 0.10% by weight to about 2.0% by weight and an average molar mass of at least 3,000 Da.
A method of forming a defoamer active, comprising:
- milling and bonding silica particles with a hydrophobilizing agent using a spiral jet mill or fluid energy mill to obtain hydrophobized silica particles,
- wherein the silica particles have a BET surface area of less than about 60 m2/g, a surface pH of at least about 10, a pore volume of about 0.25 cc/g or less, and a median particle size ranging from about 2 μm to about 50 μm, and a carbon content of the hydrophobized silica particles is not more than 3%, and
- wherein the hydrophobilizing agent is a silanol terminated polydimethylsiloxane having a content of hydroxyl group ranging from about 0.10% by weight to about 2.0% by weight and an average molar mass of at least 3,000 Da;
- and
- wherein the silanol terminated polydimethylsiloxane is present in the hydrophobized silica particles in an amount of not more than 6% by weight based on a total weight of the hydrophobized silica particles.
2 more elements
Dependencies are inferred from the claim text.