Sanyo Chemical Industries, Ltd.

Ricoh Company, Ltd.

Shuhei Yahiro

Tadao Takikawa

Tomoyuki Ichikawa

Hideki Sugiura

Yasuaki Iwamoto

Satoshi Mochizuki

Yasuhiro Ono

Toshihiko Kinsho

Hidetoshi Noda

Masakazu Iwata

Takashi Akutagawa

Yoko Sakurai

Tsuyosi Izumi

Yutaka Yoshida

The present invention concerns a method for producing an aqueous dispersion (X1), the method including a step that includes mixing an aqueous dispersion liquid (W) of resin particles (A) comprising a resin (a) with a precursor (b0) of a resin (b) or an oily liquid (OL) comprising the precursor (b0) and an organic solvent to disperse the precursor (b0) or the oily liquid (OL) in the aqueous dispersion liquid (W), followed by causing the precursor (b0) to react in the aqueous dispersion liquid (W) to form resin particles (B) comprising the resin (b), thereby obtaining the aqueous dispersion (X1) of resin particles (C) having a structure where resin particles (A) are adhered on the surface of the resin particles (B), wherein at least one of the resin (a) and the resin (b) contains a polyester resin (p1) formed in the presence of a specific titanium catalyst (t) or a resin (p2) having the polyester resin (p1) as a constituent unit.

Method for producing resin dispersions and resin particles

Disclosed is a heat-fusible electrostatic image developing toner which has an excellent balance between fixability at low temperatures and grindability and is excellent in glossiness after fixing. Also disclosed is a resin for toners. A polyester resin for toners which is obtained by polycondensing a polyol component and a polycarboxylic acid component is characterized by containing 20-100 weight % of one or more polyester resins (A1) having a storage elastic modulus from 2.5&#xd7;10Pa to 5&#xd7;10Pa at 150&#xb0; C. wherein the molar average cohesive energy of the polyol component is between 7.0&#xd7;10and 1.4&#xd7;10J.

Polyester resin for toner, toner composition and resin particle

Provided is a resin particle comprising a resin (a) and a filler (b) contained in the particle; the particle has a volume average particle diameter of from 0.1 to 300 &#x3bc;m and a shape factor of from 110 to 300; the particle has an outer shell layer (S) comprising at least a portion of the filler (b); the layer (S) is at least 0.01 &#x3bc;m thick and has a thickness that is &#xbd; or less of the maximum inscribed circle radius of the particle cross section. When used as a toner resin, it is excellent in blade cleaning properties and wide in the fixation temperature range; when employed as a paint additive or a cosmetics additive, it is excellent in masking properties; when used as paper coating additive, it is excellent in ink retention; when utilized as an abrasive, it is excellent in abrasion.

Resin particle and process of producing the same

A toner capable of making compatible a transferring property, a fixing property and a cleaning property and forming a high-precision image. The toner comprises a binder resin and a colorant and is characterized in that the average circularity of the toner is at least 0.95, a ratio (D/S) between the total projection area (S) and the contact area (D) of the toner is 15% to 40%, and the contact area (D) is a total contact area between the toner and an object surface. The toner has such a shape as to be able to contact a latent image carrier with a proper contact area, has a high transferring rate and can prevent transferring dust.

Toner, developer, image developing apparatus, and image forming apparatus

Growing community of inventors

Kyoto, Japan

Shuhei Yahiro