Toner and image forming method using magnetic material with specific tap density and linseed oil absorption

DETAILED DESCRIPTION An object of the present invention is to provide a magnetic toner or developer capable of providing a large amount of triboelectric charge.
Another object of the present invention is to provide a magnetic toner or developer capable of providing a toner image with a high image density.
A further object of the present invention is to provide a magnetic toner or developer which is excellent in resolution and reproducibility of a thin line, and which can suitably be used for developing a digital latent image.
A further object of the present invention is to provide a magnetic toner or developer with excellent environmental stability.
A further object of the present invention is to provide a magnetic toner or developer which is less liable to damage a photosensitive member surface.
A still further object of the present invention is to provide an image forming method wherein a digital electric latent image is developed by using the above-mentioned magnetic toner or developer thereby to form a toner image.
According to the present invention, there is provided a magnetic toner, comprising a binder resin and a magnetic material comprising spherical magnetic particles, wherein the magnetic material has a tap density of 1.
2-2.
5 g/cm.
sup.
3 and a linseed oil absorption of 5-30 ml/100 g.
The present invention also provides a negatively chargeable one component-type developer, comprising a negatively chargeable magnetic toner and negatively chargeable hydrophobic silica fine powder, the magnetic toner comprising a binder resin, a negative charge controller, and a magnetic material comprising spherical magnetic particles, wherein the magnetic material has a tap density of 1.
2-2.
5 g/cm.
sup.
3 and a linseed oil absorption of 5-30 ml/100 g.
The present invention further provides an image forming method, comprising: forming a digital latent image on the surface of a latent image-bearing member, forming a layer of the developer of the present invention comprising a magnetic toner on a developer-carrying member, and triboelectrically charging the magnetic toner, transferring the magnetic toner having triboelectric charge from the developer-carrying member to the latent image-bearing member in a developing position in the presence of an alternating electric field or a pulse electric field, thereby to form a toner image on the latent image-bearing member