摘要:
Disclosed herein are spinel-type spherical black iron oxide particles containing 1.5 to 17.0 wt % of Zn, and having a specific surface area of 5 to 15 m.sup.2 /g, a magnetization of not less than 70 emu/g in an external magnetic field of 1 kOe and a coercive force (Hc) of not more than the value obtained from the following expression:Hc(Oe)=15+3.times.(specific surface area of the particles).and a process for producing the same.
摘要:
Disclosed herein is iron oxide particles comprising:100 parts by weight of material iron oxide particles having a specific surface area represented by the following formula (1):6/(.rho..multidot.d.sub.3).times..phi..sub.s ( 1)wherein .rho. represents a specific gravity of said iron oxide particles, d.sub.3 represents an area-average particle diameter (0.1 .mu.m.ltoreq.d.sub.3 .ltoreq.1.0 .mu.m) and .phi..sub.s represents an area shape factor) (1.0.ltoreq..phi..sub.s .ltoreq.2.0); and0.25 to 10 parts by weight (calculated as an oxide) of the fine particles of the oxygen compound, the fine particles of the hydrate or mixed fine particles thereof of one element selected from the group consisting of Al, Si, Zr and Ti, which are adhered to the surfaces of said iron oxide particles;the increment of said specific surface area of said iron oxide particles being 1 to 6 m.sup.2 /g, and the increment of said specific surface area with respect to the amount of said fine particles being not less than 0.35.
摘要:
Disclosed herein are magnetic particles for a magnetic toner containing a low-molecular binder resin having a weight-average molecular weight of not more than 150,000, said magnetic particles comprising particulate magnetic particles containing iron as the main ingredient and having an oil absorption of not more than 24 ml/100 g and a degree of compaction of not less than 56, and a magnetic toner containing the said magnetic particles.
摘要:
Disclosed herein is iron oxide particles comprising: 100 parts by weight of material iron oxide particles having a specific surface area represented by the following formula (1): 6/(.rho..multidot.d.sub.3).times..phi..sub.S (1) wherein .rho. represents a specific gravity of said iron oxide particles, d.sub.3 represents an area-average particle diameter (0.1 .mu.m.ltoreq.d.sub.3 .ltoreq.1.0 .mu.m) and .phi..sub.S represents an area shape factor) (1.0.ltoreq..phi..sub.S .ltoreq.2.0); and 0.25 to 10 parts by weight (calculated as an oxide) of the fine particles of the oxygen compound, the fine particles of the hydrate or mixed fine particles thereof of one element selected from the group consisting of Al, Si, Zr and Ti, which are adhered to the surfaces of said iron oxide particles; the increment of said specific surface area of said iron oxide particles being 1 to 6 m.sup.2 /g, and the increment of said specific surface area with respect to the amount of said fine particles being not less than 0.35.
摘要:
A specific magnetic particle powder is described, which is included in magnetic toners used for magnetic image character recognition (MICR). The magnetic particle powder is a magnetite particle and distinguished by the facts that its residual magnetization is of 12 to 20 emu/g, its Fe.sup.2+ content is of 18.5 to 22.5% by weight, its surface is deposited with Si or Al oxide or mixture thereof and its specific surface area is of 3.5 to 9.5 m.sup.2 /g. The magnetic particle powder used as one component of the magnetic toner enables the formation of fine accurate images and the exact detection of the image.
摘要:
Disclosed herein is magnetic particles containing iron as the main component which have an average particle diameter of 0.1 to 3.0 .mu.m and a liquid absorption of not more than 18 m.infin..
摘要:
The disclosure describes coated granular magnetite particles comprising:granular magnetite particle as a core, andM.sub.x Fe.sub.2+y O.sub.z as a surface layer, wherein M is Zn or Co, 0.4.ltoreq.x.ltoreq.1, x+y=1, and 4.0.ltoreq.z.ltoreq.4.3,the amount of M in said M.sub.x Fe.sub.2+y O.sub.z being 0.5 to 6 mol % based on the total Fe content in said granular magnetite particle as a core; anda process for producing the coated granular magnetite particles.
摘要:
Disclosed herein is iron oxide particles comprising:100 parts by weight of material iron oxide particles having a specific surface area represented by the following formula (1):6/(.rho..multidot.d.sub.3).times..phi..sub.s (1) wherein .rho. represents a specific gravity of said iron oxide particles, d.sub.3 represents an area-average particle diameter (0.1 .mu.m.ltoreq.d.sub.3 .ltoreq.1.0 .mu.m) and .phi..sub.s represents an area shape factor) (1.0.ltoreq..phi..sub.s .ltoreq.2.0); and0.25 to 10 parts by weight (calculated as an oxide) of the fine particles of the oxygen compound, the fine particles of the hydrate or mixed fine particles thereof of one element selected from the group consisting of Al, Si, Zr and Ti, which are adhered to the surfaces of said iron oxide particles;the increment of said specific surface area of said iron oxide particles being 1 to 6 m.sup.2 /g, and the increment of said specific surface area with respect to the amount of said fine particles being not less than 0.35.
摘要:
Disclosed herein are composite carrier particles for electrophotography comprising 80 to 99% by weight of ferromagnetic fine particles and a phenol resin, and having a number-average particle diameter of 10 to 1,000 .mu.m, a bulk density of not more than 2.0 g /cm.sup.3, and a curved surface configuration, and a process for producing the same.
摘要:
A magnetic toner containing 100 parts by weight of magnetic Fe.sup.2+ -containing iron oxide particles having an average particle size of 0.05 to 0.30 .mu.m, containing not less than 0.9 atm % and less than 1.7 atm % of silicon, calculated as Si, based on Fe, having a substantially cubic shape each ridge of which has a curved surface, and having a ratio .phi. represented by the following formula of more than 1.0 and less than 1.4: .phi.=l/w wherein l represents an average maximum length of said Fe.sup.2+ -containing particles and w represents an average minimum length of said Fe.sup.2+ -containing particles, and 10 to 900 parts by weight of a toner resin.