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US 5,204,205 AGranted
Three layered toner for electrophotography
AssigneeMinolta Camera Kabushiki Kaisha
InventorsMasahiro Anno, Kazuo Ota, Junji Machida, Eiichi Sano, Makoto Kobayashi
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Abstract
This invention relates to toner for the development of electrostatic latent images comprising a core particle comprising at least styrene-acrylic copolymers or polyester resins, an intermediate layer coating the core particle and comprising at least styrene-acrylic copolymers, and an outermost surface layer coating the intermediate layer and comprising at least styrene-acrylic copolymers, the contents (%) of the styrenic monomer component in styrene-acrylic copolymers of which the core particles, the intermediate layers and the outermost surface layers are formed being in specified relationships.
Claims25
Toner for the development of electrostatic latent images comprising
- a core particle comprising at least styrene-acrylic copolymer,
- an intermediate layer coating the core particle and comprising at least styrene-acrylic copolymers, and
- an outermost surface layer coating the intermediate layer and comprising at least styrene-acrylic copolymers,
- an absolute value (%) of the difference between S.sub.0 (%) and S.sub.1 (%) represented by the formula (.vertline.S.sub.0 -S.sub.1 .vertline.)
- in which S.sub.0 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the core particle is formed, and S.sub.1 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the intermediate layer is formed,
- being 10% or more, and
- an absolute value (%) of the difference between S.sub.1 (%) and S.sub.2 (%) represented by the formula (.vertline.S.sub.1 -S.sub.2 .vertline.)
- in which S.sub.1 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the intermediate layer is formed and S.sub.2 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the outermost surface is formed,
- being 5% or more, and
- the relationship among S.sub.0, S.sub.1 and S.sub.2 satisfies the following formula;
- S.sub.0 >S.sub.1 >S.sub.2 or S.sub.0 <S.sub.1 <S.sub.2.
8 more elements
Toner for the development of electrostatic latent images comprising
- a core particle comprising at least polyester resins,
- an intermediate layer coating the core particle and comprising at least styrene-acrylic copolymers, and
- an outermost surface layer coating the intermediate layer and comprising at least styrene-acrylic copolymers,
- an absolute value (%) of the difference between S.sub.1 (%) and S.sub.2 (%) represented by the formula (.vertline.S.sub.1 -S.sub.2 .vertline.)
- in which S.sub.1 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the intermediate layer is formed and S.sub.2 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the outermost surface is formed,
- being 5% or more.
3 more elements
Toner for the development of electrostatic latent images comprising
- a core particle comprising at least styrene-acrylic copolymer,
- an intermediate layer coating the core particle and comprising at least styrene-acrylic copolymers, and
- an outermost surface layer coating the intermediate layer and comprising at least styrene-acrylic copolymers, an absolute value (%) of the difference between S.sub.0 (%) and S.sub.1 (%) represented by the formula (.vertline.S.sub.1 -S.sub.0 .vertline.) in which S.sub.0 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the core particle is formed, and S.sub.1 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the intermediate layer is formed,
- being 10% or more, and
- an absolute value (%) of the difference between S.sub.1 (%) and S.sub.2 (%) represented by the formula (.vertline.S.sub.2 -S.sub.1 .vertline.)
- in which S.sub.1 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the intermediate layer is formed and S.sub.2 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the outermost surface is formed,
- being 10% or more, and
- the relationship among S.sub.0, S.sub.1 and S.sub.2 satisfying the following formula;
- S.sub.0 >S.sub.1 and S.sub.1 <S.sub.2, or
- S.sub.0 <S.sub.1 and S.sub.1 >S.sub.2, and
- a coloring agent being contained in the core particle and/or the intermediate layer, and
- the coloring agent-containing layer being formed of styrene-acrylic copolymers having the lowest viscosity.
9 more elements
Toner for the development of electrostatic latent images comprising
- core particles comprising at least thermoplastic resin and having a means particle size of 1 to 20 .mu.m,
- an intermediate layer comprising at least styrene-acrylic copolymers and having a layer thickness of 0.05 to 4 .mu.m,
- an outermost surface layer comprising at least styrene-acrylic copolymers and a charge controlling agent, and having a layer thickness of 0.05 to 4 .mu.m,
- an absolute value (%) of the difference between S.sub.1 (%) and S.sub.2 (%) represented by the formula (.vertline.S.sub.1 -S.sub.2 .vertline.)
- in which S.sub.1 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the intermediate layer is formed and S.sub.2 is a content (%) of styrenic monomer component in the styrene-acrylic copolymers of which the outermost surface is formed, being 5% or more, and
- a coloring agent being contained in the core particles and/or the intermediate layer.
3 more elements
Dependencies are inferred from the claim text.