Hydrophilic and highly oil absorbent boron nitride powder, method for manufacturing the same, and cosmetic
AssigneeMizushima Ferroalloy Co., Ltd.
InventorsTakahisa Koshida, Masato Kumagai, Shoichi Hiwasa
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Abstract
A boron nitride powder including flat-shaped primary particles of BN and an aggregate of the primary particles has a water permeation speed not less than 1 mm2/s and oil absorption of 100 ml/100 g to 500 ml/100 g, which is a cosmetic boron nitride powder with high hydrophilicity and high oil absorbency. The use of such a boron nitride powder provides a cosmetic that is significantly improved not only in gloss finish and transparency (bare skin feeling) but also in sustainability.
Claims8
A hydrophilic and highly oil absorbent boron nitride powder, washed in a liquid that contains surfactant, comprising flat-shaped primary particles of BN and an aggregate of the primary particles,
- wherein a water permeation speed is not less than 1 mm2/s, and oil absorption is 100 ml/100 g to 500 ml/100 g.
A method for manufacturing a hydrophilic and highly oil absorbent boron nitride powder, the method comprising:
- heating at least one of boric acid and a dehydration product thereof, at least one of urea and a compound thereof, and boron carbide in an inert atmosphere to obtain a boron nitride powder having a turbostratic structure;
- heat-treating the obtained boron nitride powder at a temperature of 1500° C. to 2300° C. in an inert atmosphere;
- grinding the heat-treated boron nitride powder;
- and
- washing primary particles of boron nitride obtained as a result of the grinding in a washing liquid that contains a surfactant, and drying the washed primary particles.
Dependencies are inferred from the claim text.