Carrier for electrophotographic use
AssigneeKonica Corporation
InventorsMasafumi Uchida, Kishio Tamura, Tsuneo Daidoji
Life of this patent
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Abstract
A carrier for electrophotographic use is disclosed. The carrier has a resin-coated layer on the surface of the core member. The resin forming the coated layer contains a polymer prepared by copolymerizing an alicyclic methacrylate monomer and a chain-type methacrylate monomer. A high quality image can stably be obtained extending over a long period of time when the carrier is used in continuous developing.
Claims19
A carrier for electrophotographic use having a resin-coated layer on the surface of the core member thereof, wherein said coated layer contains a copolymer having a Tg of 60.degree. to 180.degree. C. comprising a cyclohexyl methacrylate first monomer unit, with a second monomer unit of methylmethacrylate, ethylmethacrylate, propylmethacrylate, n-butylmethacrylate, hexylmethacrylate, octylmethacrylate or 2-ethylhexylmethacrylate and contains unpolymerized monomers in an amount of 10 to 2000 ppm relative to the whole coated layer and a surfactant in an amount of 5 to 1000 ppm relative to the whole coated layer.
A carrier for electrophotographic use having a resin-coated layer on the surface of the core member thereof, wherein said coated layer contains a mixture of a first polymer having a Tg of 60.degree. to 180.degree. C. comprising a cyclohexyl methacrylate monomer unit, and a second polymer having a Tg of 60.degree. to 180.degree. C. comprising a methylmethacrylate monomer unit, and contains unpolymerized monomers in an amount of 10 to 2000 ppm relative to the whole coated layer and a surfactant in an amount of 5 to 1000 ppm relative to the whole coated layer.
The carrier for electrophotographic use as claimed 10, wherein the first and second polymers each have a softening point of 150.degree. to 300.degree. C.
A carrier for electrophotographic use having a resin-coated layer on the surface of the core member thereof, wherein said coated layer containing a copolymer having a Tg of 80.degree. to 150.degree. C. and having a weight average molecular weight of 10,000 to 800,000 obtained by copolymerizing cyclohexyl methacrylate with methylmethacrylate, ethylmethacrylate, propylmethacrylate, n-butylmethacrylate, hexylmethacrylate, octylmethacrylate or 2-ethylhexyl-methacrylate, and containing unpolymerized monomers in an amount of 10 to 2000 ppm relative to the whole coated layer and a surfactant in an amount of 5 to 1000 ppm relative to the whole coated layer.
Dependencies are inferred from the claim text.