MAGNETIC CARRIER, TWO-COMPONENT DEVELOPER AND MANUFACTURING METHOD OF MAGNETIC CARRIER

• Main Authors: KAMAE KENTARO, HASHIMOTO TAKESHI, OTSU TAKESHI, IDA HAYATO, SHIROYAMA KAZUHISA
• Format: Patent
• Language: English; Japanese
• Published: 27.05.2021
• Subjects: CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

To provide a magnetic carrier which suppresses the abrasion of a coating layer of the magnetic carrier and shows the excellent charge-imparting property, leak suppression property and image density stability.SOLUTION: A magnetic carrier includes a magnetic core particle and a magnetic carrier particle that has a coating layer of an organic silicon polymer on the magnetic core particle surface. The organic silicon polymer has a structure expressed by the following formula (T3). In 29Si-NMR measurement for THF insoluble of the organic silicon polymer, a ratio ST3 of a peak area of the structure expressed by the following formula (T3) to the entire peak area of the organic silicon polymer is equal to or greater than 0.05. In the roughness curve measured by a scan type probe microscope of the magnetic carrier particle, a ratio (σ/RSm) to RSm of a standard deviation σ between the average length RSm of a roughness curve element of the magnetic carrier particle and the length of a portion having irregularity for one cycle is within a specific range. (T3) R-Si(O1/2)3. In the formula, R represents the specific substituent group.SELECTED DRAWING: None 【課題】磁性キャリアの被覆層の摩耗を抑制し、優れた帯電付与性、リーク抑制性、画像濃度安定性を示す磁性キャリア。【解決手段】磁性コア粒子及び該磁性コア粒子表面の有機ケイ素重合体の被覆層を有する磁性キャリア粒子を有する磁性キャリアであって、該有機ケイ素重合体が、下記式（Ｔ３）で示される構造を有し、該有機ケイ素重合体のＴＨＦ不溶分の２９Ｓｉ−ＮＭＲ測定において、該有機ケイ素重合体の全ピーク面積に対する、下記式（Ｔ３）で表される構造のピーク面積の割合ＳＴ３が、０．０５以上であり、該磁性キャリア粒子の走査型プローブ顕微鏡で測定される粗さ曲線において、該磁性キャリア粒子の粗さ曲線要素の平均長さＲＳｍ及び１周期分の凹凸が生じている部分の長さの標準偏差σの、該ＲＳｍに対する比（σ／ＲＳｍ）が特定の範囲である磁性キャリア。Ｒ−Ｓｉ（Ｏ１／２）３（Ｔ３）式中、Ｒは特定の置換基を示す。【選択図】なし