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US 5,958,641 AGranted
Single component toner comprising specified polyester
AssigneeMinolta Co., Ltd.
InventorsTetsuo Sano, Hiroyuki Fukuda, Chikara Tsutsui, Choichiro Tanigawa, Senyu Taira, Mikihiko Sukeno
Life of this patent
Estimating the term…
Abstract
This invention relates to a single component toner comprising specified polyester resins as binder resin and used in single-component developing system in which toner particles are electrically charged when passing through the opening between a toner-levelling member and a toner-transporting member positioned against a photosensitive member.
Claims13
A single-component toner comprising:
- a binder resin comprising linear polyester resin (A) and polyester resin (B) bonded with urethane bonds, and a colorant, said linear polyester resin (A) composed of at least an etherified diphenol and an aromatic dicarboxylic acid, and having a weight average molecular weight of 5000 to 12000, a glass transition point of 60 to 80.degree. C., an acid value of 45 KOHmg/g or less and a molar ratio (carboxyl group/hydroxyl group) of 1.1 to 1.4;
- said polyester resin (B) composed of at least an etherified diphenol, an aromatic dicarboxylic acid, and at least one compound selected from the group consisting of aliphatic diols, polyols having three hydroxyl groups or more, aliphatic dicarboxylic acids substituted by C.sub.3 -C.sub.20 alkyl group and diols substituted by C.sub.3 -C.sub.20 alkyl group, and having a molar ratio (hydroxyl group/carboxyl group) of 1.1 to 1.4, a weight average molecular weight of 5000 to 12000 and a glass transition point of 20 to 50.degree. C.;
- and said binder resin prepared by mixing the linear polyester resin (A) and the polyester resin (B) which differs from the linear polyester resin (A) and treating the obtained mixture with an isocyanate compound to form said urethane bonds for chain prolongation.
A single-component toner comprising:
- a binder resin comprising a linear polyester resin (A) and a polyester resin (B) bonded with urethane bonds, and a colorant, said linear polyester resin (A) having a molar ratio (carboxyl group/hydroxyl group) of 1.1 to 1.4, a weight average molecular weight of 5000 to 12000, a glass transition point of 60 to 80.degree. C. and an acid value of 45 KOHmg/g or less, said polyester resin (B) having a molar ratio (hydroxyl group/carboxyl group) of 1.1 to 1.4, a weight average molecular weight of 5000 to 12000 and a glass transition point of 20 to 50.degree. C.;
- and said binder resin prepared by mixing the linear polyester resin (A) and the polyester resin (B) which differs from the linear polyester resin (A) and treating the obtained mixture with an isocyanate compound to form said urethane bonds, wherein said toner further comprises an off-set prevention agent.
A single-component toner comprising:
- a binder resin comprising a linear polyester resin (A) and a polyester resin (B) bonded with urethane bonds, and a colorant, said linear polyester resin (A) having a molar ratio (carboxyl group/hydroxyl group) of 1.1 to 1.4, a weight average molecular weight of 5000 to 12000, a glass transition point of 60 to 80.degree. C. and an acid value of 45 KOHmg/g or less, said polyester resin (B) having a molar ratio (hydroxyl group/carboxyl group) of 1.1 to 1.4, a weight average molecular weight of 5000 to 12000 and a glass transition point of 20 to 50.degree. C.;
- and said binder resin prepared by mixing the linear polyester resin (A) and the, polyester resin (B) which differs from the linear polyester resin (A) and treating the obtained mixture with an isocyanate compound to form said urethane bonds, wherein said binder resin has a glass transition point of 60 to 80.degree. C. and a softening point of 110 to 170.degree. C. and contains an insoluble component which is insoluble in methyl ethyl ketone at a content of 10 to 40 percent by weight.
A single-component toner comprising:
- a binder resin comprising a linear polyester resin (A) and a polyester resin (B) bonded with urethane bonds, and a colorant, said linear polyester resin (A) having a molar ratio (carboxyl group/hydroxyl group) of 1.1 to 1.4, a weight average molecular weight of 5000 to 12000, a glass transition point of 60 to 80.degree. C. and an acid value of 45 KOHmg/g or less, said polyester resin (B) having a molar ratio (hydroxyl group/carboxyl group) of 1.1 to 1.4, a weight average molecular weight of 5000 to 12000 and a glass transition point of 20 to 50.degree. C.;
- and said binder resin prepared by mixing the linear polyester resin (A) and the polyester resin (B) which differs from the linear polyester resin (A) and treating the obtained mixture with an isocyanate compound to form said urethane bonds, wherein said binder resin has an acid value of 25 KOHmg/g or less.
Dependencies are inferred from the claim text.