The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 16, 2019
Filed:
Jul. 24, 2015
Denka Company Limited, Tokyo, JP;
DENKA COMPANY LIMITED, Tokyo, JP;
Abstract
Provided is an external additive for toner, which is suitable for producing a toner having excellent storage stability and chargeability. A silica fine powder suitable for being added to the external additive for toner is also provided. The silica fine powder has a specific surface area of 15 m/g or more and 90 m/g or less, a loose bulk density of 0.09 g/cmor more and 0.18 g/cmor less, a carbon content of 0.25 wt % or more and 0.90 wt % or less, and a hydrophobicity of 60% or more and 75% or less. It is preferable that a ratio (A)/(B) of the loose bulk density of the silica fine powder after surface treatment (A) to a loose bulk density of the silica fine powder before the surface treatment (B) be 1.05 or more and 1.60 or less.