US5618647A — Magnetic toner and image forming method

Claim 1

Independent Claim 150 words

A magnetic toner comprising magnetic toner particles containing a binder resin and a magnetic material, and an inorganic fine powder treated with an organic compound, wherein said magnetic toner has: a volume average particle diameter D v (μm) of 3 μm≦D v <6 μm; a weight average particle diameter D 4 (μm) of 3.5 μm≦D 4 <6.5 μm; a percentage M r of particles with particle diameters of 5 μm or smaller in number particle size distribution of the magnetic toner, of 60% by number<M r ≦90% by number; and a ratio of a percentage N r of particles with particle diameters of 3.17 μm or smaller in number particle size distribution of the magnetic toner to a percentage N v of particles with particle diameters of 3.17 μm or smaller in volume particle size distribution of the magnetic toner, N r /N v , of from 2.0 to 8.0.

Claim 2

Dependent Claim 150 words

A magnetic toner comprising magnetic toner particles containing a binder resin and a magnetic material, and an inorganic fine powder treated with an organic compound, wherein said magnetic toner has: a volume average particle diameter D v (μm) of 3 μm≦D v <6 μm; a weight average particle diameter D 4 (μm) of 3.5 μm≦D 4 <6.5 μm; a percentage M r of particles with particle diameters of 5 μm or smaller in number particle size distribution of the magnetic toner, of 60% by number<M r ≦90% by number; and a ratio of a percentage N r of particles with particle diameters of 3.17 μm or smaller in number particle size distribution of the magnetic toner to a percentage N v of particles with particle diameters of 3.17 μm or smaller in volume particle size distribution of the magnetic toner, N r /N v , of from 2.0 to 8.0.

Claim 3

Dependent Claim 68 words

The magnetic toner according to claim 1, wherein the ratio of a percentage N r of particles with particle diameters of 3.17 μm or smaller in number particle size distribution of the magnetic toner to a percentage N v of particles with particle diameters of 3.17 μm or smaller in volume particle size distribution of the magnetic toner, N r /N v , is from 3.0 to 7.0.

Claim 4

Dependent Claim 37 words

The magnetic toner according to claim 1, wherein said magnetic toner has a volume percentage of particles with particle diameters of 8 μm or larger in volume particle size distribution, of not more than 10% by volume.

Claim 5

Dependent Claim 40 words

The magnetic toner according to claim 1, wherein said inorganic fine powder treated with an organic compound is a fine powder of a material selected from the group consisting of titania, alumina, silica and a composite of any of these.

Claim 6

Dependent Claim 29 words

The magnetic toner according to claim 1, wherein said magnetic toner has an absolute value Q (mC/g) of quantity of triboelectricity with respect to iron powder, of 14≦Q≦80 mC/kg.

Claim 7

Dependent Claim 29 words

The magnetic toner according to claim 5, wherein said magnetic toner has an absolute value Q (mC/g) of quantity of triboelectricity with respect to iron powder, of 14≦Q≦60 mC/kg.

Claim 8

Dependent Claim 29 words

The magnetic toner according to claim 6, wherein said magnetic toner has an absolute value Q (mC/g) of quantity of triboelectricity with respect to iron powder, of 24<Q≦55 mC/kg.

Claim 9

Dependent Claim 26 words

The magnetic toner according to claim 1, wherein said inorganic fine powder is treated on its particle surfaces, with an silicone oil or a silicone varnish.

Claim 10

Dependent Claim 40 words

The magnetic toner according to claim 1, wherein said magnetic material is formed of a metal oxide having a magnetization intensity of greater than 50 Am 2 /kg (emu/g) under application of a magnetic field of 79.6 kA/m (1,000 oersteds).

Claim 11

Dependent Claim 19 words

The magnetic toner according to claim 1, wherein said magnetic toner particles contain a liquid lubricant inside the particles.

Claim 12

Dependent Claim 17 words

The magnetic toner according to claim 10, wherein said liquid lubricant is supported on the magnetic material.

Claim 13

Dependent Claim 19 words

The magnetic toner according to claim 10, wherein said liquid lubricant is supported on particles to form lubricating particles.

Claim 14

Dependent Claim 42 words

The magnetic toner according to claim 12, wherein said lubricating particles are formed of from 20 parts by weight to 90 parts by weight of the liquid lubricant and from 80 parts by weight to 10 parts by weight of the particles.

Claim 15

Dependent Claim 24 words

The magnetic toner according to claim 10, wherein said liquid lubricant has a viscosity at 25° C., of from 10 cSt to 200,000 cSt.

Claim 16

Dependent Claim 16 words

The magnetic toner according to claim 1, which further contains lubricating particles supporting a liquid lubricant.

Claim 17

Dependent Claim 26 words

The magnetic toner according to claim 15, wherein said lubricating particles have from 20 parts by weight to 90 parts by weight of the liquid lubricant.

Claim 18

Dependent Claim 24 words

The magnetic toner according to claim 15, wherein said liquid lubricant has a viscosity at 25° C., of from 10 cSt to 200,000 cSt.

Claim 19

Dependent Claim 22 words

The magnetic toner according to claim 15, wherein said lubricating particles are formed of the liquid lubricant and fine inorganic compound particles.

Claim 20

Dependent Claim 22 words

The magnetic toner according to claim 15, wherein said lubricating particles are formed of the liquid lubricant and fine organic compound particles.

Claim 21

Dependent Claim 45 words

The magnetic toner according to claim 18, wherein said lubricating particles are formed of from 20 parts by weight to 90 parts by weight of the liquid lubricant and from 80 parts by weight to 10 parts by weight of the fine inorganic compound particles.

Claim 22

Dependent Claim 25 words

The magnetic toner according to claim 20, wherein said liquid lubricant is a silicone oil, and said fine inorganic compound particles are fine silica particles.

Claim 23

Dependent Claim 38 words

The magnetic toner according to claim 1, wherein said magnetic material has a sphericity φ of 0.8 or more and has a silicon element content of from 0.5% by weight to 4% by weight based on iron element.

Claim 24

Dependent Claim 25 words

The magnetic toner according to claim 1, wherein the percentage M r of said magnetic toner is from 62% by number to 88% by number.

Claim 25

Dependent Claim 245 words

An image forming method comprising: electrostatically charging an electrostatic latent image bearing member through a charging means; exposing the charged electrostatic latent image bearing member to light to form an electrostatic latent image on the electrostatic latent image bearing member; developing the electrostatic latent image through a developing means having a magnetic toner, to form a magnetic toner image on the electrostatic latent image bearing member; transferring the magnetic toner image to a transfer medium via, or not via, an intermediate transfer medium through a transfer means to which a bias voltage is applied, wherein said magnetic toner comprises magnetic toner particles containing a binder resin and a magnetic material, and an inorganic fine powder treated with an organic compound, wherein said magnetic toner has; a volume average particle diameter D v (μm) of 3 μm≦D v <6 μm; a weight average particle diameter D 4 (μm) of 3.5 μm≦D 4 <6.5 μm; a percentage M r of particles with particle diameters of 5 μm or smaller in number particle size distribution of the magnetic toner, of 60% by number<M r ≦90% by number; and a ratio of a percentage N r or particles with particle diameters of 3.17 μm or smaller in number particle size distribution of the magnetic toner to a percentage N v of particles with particle diameters of 3.17 μm or smaller in volume particle size distribution of the magnetic toner, N r /N v , of from 2.0 to 8.0.

Claim 26

Dependent Claim 245 words

An image forming method comprising: electrostatically charging an electrostatic latent image bearing member through a charging means; exposing the charged electrostatic latent image bearing member to light to form an electrostatic latent image on the electrostatic latent image bearing member; developing the electrostatic latent image through a developing means having a magnetic toner, to form a magnetic toner image on the electrostatic latent image bearing member; transferring the magnetic toner image to a transfer medium via, or not via, an intermediate transfer medium through a transfer means to which a bias voltage is applied, wherein said magnetic toner comprises magnetic toner particles containing a binder resin and a magnetic material, and an inorganic fine powder treated with an organic compound, wherein said magnetic toner has; a volume average particle diameter D v (μm) of 3 μm≦D v <6 μm; a weight average particle diameter D 4 (μm) of 3.5 μm≦D 4 <6.5 μm; a percentage M r of particles with particle diameters of 5 μm or smaller in number particle size distribution of the magnetic toner, of 60% by number<M r ≦90% by number; and a ratio of a percentage N r or particles with particle diameters of 3.17 μm or smaller in number particle size distribution of the magnetic toner to a percentage N v of particles with particle diameters of 3.17 μm or smaller in volume particle size distribution of the magnetic toner, N r /N v , of from 2.0 to 8.0.

Claim 27

Dependent Claim 25 words

The image forming method according to claim 24, wherein said charging means comes into contact with the surface of the electrostatic latent image bearing member.

Claim 28

Dependent Claim 31 words

The image forming method according to claim 24, wherein said transfer means is so provided as to come into pressure contact with the surface of the electrostatic latent image bearing member.

Claim 29

Dependent Claim 33 words

The image forming method according to claim 24, wherein said electrostatic latent image bearing member is cleaned through a cleaning means after the magnetic toner image has been transferred to the transfer medium.

Claim 30

Dependent Claim 36 words

The image forming method according to claim 24, wherein said developing means has a toner carrying member and a toner layer thickness control member, and an alternating electric field is applied to the toner carrying member.

Claim 31

Dependent Claim 26 words

The image forming method according to claim 24, wherein said toner carrying member is covered on its surface with a resin layer containing conductive fine particles.

Claim 32

Dependent Claim 22 words

The image forming method according to claim 24, wherein said toner carrying member is internally provided with a magnetic field generating means.

Claim 33

Dependent Claim 21 words

The image forming method according to claim 24, wherein said electrostatic latent image bearing member is an organic photoconductor photosensitive member.

Claim 34

Dependent Claim 30 words

The image forming method according to claim 24, wherein said electrostatic latent image bearing member has the surface with a contact angle to water of not smaller than 85 degrees.

Claim 35

Dependent Claim 30 words

The image forming method according to claim 31, wherein said electrostatic latent image bearing member has the surface with a contact angle to water of not smaller than 90 degrees.

Claim 36

Dependent Claim 26 words

The image forming method according to claim 29, wherein said resin layer of the toner carrying member further has particles for forming irregularities on its surface.

Claim 37

Dependent Claim 23 words

The image forming method according to claim 24, wherein said electrostatic latent image bearing member has on its surface a layer containing fluorine.

Claim 38

Dependent Claim 69 words

The image forming method according to claim 24, wherein the ratio of a percentage N r of particles with particle diameters of 3.17 μm or smaller in number particle size distribution of the magnetic toner to a percentage N v of particles with particle diameters of 3.17 μm or smaller in volume particle size distribution of the magnetic toner, N r /N v , is from 3.0 to 7.0.

Claim 39

Dependent Claim 38 words

The image forming method according to claim 24, wherein said magnetic toner has a volume percentage of particles with particle diameters of 8 μm or larger in volume particle size distribution, of not more than 10% by volume.

Claim 40

Dependent Claim 41 words

The image forming method according to claim 24, wherein said inorganic fine powder treated with an organic compound is a fine powder of a material selected from the group consisting of titania, alumina, silica and a composite of any of these.

Claim 41

Dependent Claim 30 words

The image forming method according to claim 24, wherein said magnetic toner has an absolute value Q (mC/g) of quantity of triboelectricity with respect to iron powder, of 14≦Q≦80 mC/kg.

Claim 42

Dependent Claim 30 words

The image forming method according to claim 39, wherein said magnetic toner has an absolute value Q (mC/g) of quantity of triboelectricity with respect to iron powder, of 14≦Q≦60 mC/kg.

Claim 43

Dependent Claim 30 words

The image forming method according to claim 40, wherein said magnetic toner has an absolute value Q (mC/g) of quantity of triboelectricity with respect to iron powder, of 24<Q≦55 mC/kg.

Claim 44

Dependent Claim 27 words

The image forming method according to claim 24, wherein said inorganic fine powder is treated on its particle surfaces, with an silicone oil or a silicone varnish.

Claim 45

Dependent Claim 41 words

The image forming method according to claim 24, wherein said magnetic material is formed of a metal oxide having a magnetization intensity of greater than 50 Am 2 /kg (emu/g) under application of a magnetic field of 79.6 kA/m (1,000 oersteds).

Claim 46

Dependent Claim 20 words

The image forming method according to claim 24, wherein said magnetic toner particles contain a liquid lubricant inside the particles.

Claim 47

Dependent Claim 18 words

The image forming method according to claim 44, wherein said liquid lubricant is supported on the magnetic material.

Claim 48

Dependent Claim 20 words

The image forming method according to claim 44, wherein said liquid lubricant is supported on particles to form lubricating particles.

Claim 49

Dependent Claim 43 words

The image forming method according to claim 46, wherein said lubricating particles are formed of from 20 parts by weight to 90 parts by weight of the liquid lubricant and from 80 parts by weight to 10 parts by weight of the particles.

Claim 50

Dependent Claim 25 words

The image forming method according to claim 44, wherein said liquid lubricant has a viscosity at 25° C., of from 10 cSt to 200,000 cSt.

Claim 51

Dependent Claim 20 words

The image forming method according to claim 24, wherein said magnetic toner further contains lubricating particles supporting a liquid lubricant.

Claim 52

Dependent Claim 27 words

The image forming method according to claim 49, wherein said lubricating particles have from 20 parts by weight to 90 parts by weight of the liquid lubricant.

Claim 53

Dependent Claim 25 words

The image forming method according to claim 49, wherein said liquid lubricant has a viscosity at 25° C., of from 10 cSt to 200,000 cSt.

Claim 54

Dependent Claim 23 words

The image forming method according to claim 49, wherein said lubricating particles are formed of the liquid lubricant and fine inorganic compound particles.

Claim 55

Dependent Claim 23 words

The image forming method according to claim 49, wherein said lubricating particles are formed of the liquid lubricant and fine organic compound particles.

Claim 56

Dependent Claim 46 words

The image forming method according to claim 52, wherein said lubricating particles are formed of from 20 parts by weight to 90 parts by weight of the liquid lubricant and from 80 parts by weight to 10 parts by weight of the fine inorganic compound particles.

Claim 57

Dependent Claim 26 words

The image forming method according to claim 54, wherein said liquid lubricant is a silicone oil, and said fine inorganic compound particles are fine silica particles.

Claim 58

Dependent Claim 39 words

The image forming method according to claim 24, wherein said magnetic material has a sphericity φ of 0.8 or more and has a silicon element content of from 0.5% by weight to 4% by weight based on iron element.

Claim 59

Dependent Claim 26 words

The image forming method according to claim 24, wherein the percentage M r of said magnetic toner is from 62% by number to 88% by number.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-04-07	2000-10-07	2001-04-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-04-07	2004-10-07	2005-04-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-04-07	2008-10-07	2009-04-08	$7700.00	Window Closed / Lapsed

Magnetic toner and image forming method

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