Ricoh Company, Ltd.

Ken Umehara

Masami Tomita

Hideki Sugiura

Osamu Uchinokura

Hiroyuki Fushimi

Takahiro Honda

Hyo Shu

A toner is provided that comprises a colorant and a binder resin, wherein the binder resin comprises a polyester resin that is prepared by a polycondensation reaction in the presence of at least a titanium-containing catalyst expressed by General Formula (II) or (II), the toner has a volume average particle diameter of 2.0 &#x3bc;m to 10.0 &#x3bc;m and a ratio Dv/Dn within a range of 1.00 to 1.40, in which Dv represents a volume average particle diameter and Dn represents a number average particle diameter,Ti(&#x2014;X)m(&#x2014;OH)n&#x2003;&#x2003;General Formula (I)O&#x2550;Ti(&#x2014;X)p(&#x2014;OR)q&#x2003;&#x2003;General Formula (II) in General Formulas (I) and (II), X represents a residue of a mono-alkanolamine of 2 to 12 carbon atoms or a polyalkanolamine from which a hydrogen atom of one hydroxyl group is removed; other hydroxyl group(s) and still other hydroxyl group(s), within the polyalkanolamine molecule that has a directly bonding Ti atom, may polycondense to form a ring structure; other hydroxyl group(s) and still other hydroxyl group(s) may polycondense intermolecularly to form a repeating structure; and the polymerization degree is 2 to 5 in a case of forming the repeating structure; R represents one of a hydrogen atom and alkyl groups of 1 to 8 carbon atoms that may have 1 to 3 ether bonds; 'm' is an integer of 1 to 4; 'n' is an integer of 0 to 3; the sum of &#x201c;m&#x201d; and &#x201c;n&#x201d; is 4; &#x201c;p&#x201d; is an integer of 1 or 2; &#x201c;q&#x201d; is an integer of 0 or 1; the sum of &#x201c;p&#x201d; and &#x201c;q&#x201d; is 2; and in a case that &#x201c;m&#x201d; and &#x201c;p&#x201d; is 2 or more, the respective Xs may be identical or different each other.

Electrostatic image developing toner, toner kit and image forming apparatus

Provided is an electrostatic image developing toner excellent in blocking resistance at high temperature and humidity, as well as in low temperature-fixing property, having a polyester resin toner binder. Provided is the electrostatic image developing toner containing at least one noncrystalline polyester resin and a crystalline polyester resin, wherein the polyester resins are formed in the presence of at least one titanium-containing catalyst expressed in the following Formulas:Ti(&#x2014;X)(&#x2014;OH)O&#x2550;Ti(&#x2014;X)(&#x2014;OR)

Electrostatic image developing toner and image forming apparatus using the same

A toner is provided including a binder resin; a release agent; a colorant; and a fatty acid amide compound, wherein the binder resin includes: an amorphous polyester (A) having a softening point of from 70 to 140&#xb0; C.; an amorphous polyester (B) having a softening point of from 120 to 190&#xb0; C.; and a crystalline polyester (C), and wherein the following relationship is satisfied: TmC&#x3c;Tm(Asp), wherein TmC represents a softening point of the crystalline polyester (C) and Tm (Asp) represents a softening point of the fatty acid amide compound; and a developer and an image forming apparatus using the toner.

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Chiba, Japan

Ken Umehara