Dry toner and image forming method using same
AssigneeRicoh Company, Ltd.
InventorsTsunemi Sugiyama, Shigeru Emoto, Hiroshi Yamashita, Masami Tomita, Kazuhito Watanabe, Chiaki Tanaka
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Abstract
A dry toner including at least a modified polyester as a toner binder, wherein the modified polyester has a main peak in a molecular weight region of 1000 to 30000 in a molecular weight distribution as measured by GPC, contains 1 to 10% of a component having a molecular weight of at least 30000, and has an Mw/Mn ratio of not greater than 15.
Claims35
A dry toner, comprising a toner binder comprising a modified polyester selected from the group consisting of an amine-modified polyester, an acryl-modified polyester, a styrene-modified polyester, a silicone-modified polyester and mixtures thereof, wherein the modified polyester has a molecule weight distribution according to gel permeation chromatography having (a) a main peak is present in a molecular weight region of 1000 to 30,000, (b) that portion of the modified polyester having a molecule weight of at least 30,000 accounts for 1 to 10% based on a total weight of the modified polyester, and (c) a ratio (Mw/Mn) of the weight average molecular weight Mw of the modified polyester to the number average molecular weight Mn of the modified polyester is not smaller than 2 but not greater than 15.
A dry toner having a melt viscosity at 110° C. of 2.0×103 to 2.0×104 Pa.s and a melt viscosity at 130° C. of 2.0×103 or less and providing such a fixed image on an overhead projector sheet that has a deposition amount of 0.8-1.2 mg/cm2 and has a contact angle to water to water of 90°-130°.
A dry toner comprising a toner binder comprising a modified polyester, wherein the toner is obtained by:
- dissolving or dispering a toner compostion comprising a polyester-based prepolymer and a colorant in an organic solvent to prepare a liquid,
- dispering said liquid in an aqueous medium in the presence of an inorganic dispersant or a powdery polymer to obtain a dispersion,
- subjecting said dispersion to a polyaddition reaction to polymerize said prepolymer and to obtain a reaction mixture;
- and
- removing the solvent from said reaction mixture to from the toner.
Dependencies are inferred from the claim text.