Hodogaya Chemical Co., Ltd.

Ricoh Company, Ltd.

Nippon Aerosil Co., Ltd.

Masaki Okubo

Hideyuki Otsuka

Masami Ito

Yoshikazu Aoki

Jun Watanabe

Masafumi Umekawa

Masateru Yasumura

Naohiro Tarumoto

Tetsuya Yoshida

Motonori Tsuji

Masaya Tojo

Masafumi Asakai

Kazuo Nemoto

Eisuke Yamada

Masaomi Sasaki

Takeshi Yamamoto

Tomoyuki Shimada

Tamotsu Aruga

Mitsutoshi Anzai

Hisao Okada

Osamu Mukudai

Shinji Otani

Ikuo Kimura

Masataka Sawano

Kanae Hiraishi

Yuki Amano

Noriyuki Suzuki

Hiroshi Nanaumi

Naohiro Naito

Kenichi Sato

Masafumi Ota

Tatsuji Orita

To provide a charge control agent and a toner having a superior charging characteristic. A charge control agent containing a bis-phthalimide derivative represented by formula. Thus, it is possible to provide a safe, negative chargeability charge control agent with which the rate of rise of the charge can be increased, and which has a high charging amount and poses no problem in terms of waste regulations. Furthermore, it is possible to provide a negatively chargeable toner (and particularly, a negatively chargeable polymerized toner) for electrostatic image development which uses this charging control agent and has a superior charging characteristic.

Charge control agent and toner using same

The present invention provides a toner that includes a charge control agent containing one or two or more resorcin derivatives represented by the following formula (1), a colorant, and a binder resin. 

Toner, developer, and toner cartridge

The present invention is a toner for developing electrostatic charge image containing a wax derived from a plant cholesterol, an electric charge-controlling agent, a coloring agent and a binding resin. The toner is suited for use in the electromagnetic induction-heated fixing system which is capable of heating the heating member up to a predetermined fixing temperature in a short period of time, makes it possible to maintain images free of irregular luster or fouling for extended periods of time and is, further, suited for being fixed at a low temperature.

Toner for developing electrostatic charge image

Provided by the present invention is a surface-modified silica powder, characterized in that the said powder is obtained by surface treatment of a silica powder with one or two or more of a compound (A) and with an aminosilane (B), wherein the fixing rate of the compound (A) and the aminosilane (B) is a total of 50% or more, the hydrophobic rate is 80% or more, and the triboelectrostatic charge amount is 200 &#x3bc;C/g or less in its absolute value. The surface-modified silica powder of the present invention can stabilize many properties including fluidity and electrostatic properties while can significantly reduce problems such as fogging and decrease in image quality without significantly deteriorating characteristics of a developing agent and so forth when this is used as an external additive.

Surface-modified silica powder and method for producing the same, as well as toner composition for electrophotography

A modified charge control agent composition comprising a metal compound (A) of aromatic hydroxycarboxylic acid bonded with a metal atom selected from a zirconium atom, a calcium atom, an aluminum atom, a chromium atom, a boron atom, and a zinc atom via at least one of an ionic bond, a covalent bond, and a coordinate bond; and at least one inorganic pigment (B), wherein the pigment (B) is contained in an amount of fromtoparts by mass inparts by mass of the composition. The modified charge control agent composition exhibits a high charge-imparting effect, and an electrostatic image developing toner that contains the charge control agent composition will have a high electrostatic charge amount and a high environmental stability.

Charge control agent composition and toner utilizing the same

The present invention discloses a mixed cyclic phenol sulfide which is a mixture of the cyclic phenol sulfide wherein m is 8 and the cyclic phenol sulfide wherein m is an integer other than 8, the cyclic phenol sulfide being represented by the following formula (1): wherein R is a straight or branched alkyl group having 1 to 6 carbon atoms, and m is an integer from 4 to 9; or a cyclic phenol sulfide of formula (1) wherein m is 8. The present invention also discloses a charge control agent which comprises the above sulfide(s) as the active ingredient; and a toner which comprises the charge control agent, a coloring agent and a binder resin. This charge control agent is particularly useful for color toners, and it speeds up charging risetime, and has a high charge amount and charging characteristics excellent in the environmental stability. Further, the charge control agent is safe since it does not have any problem with the waste regulations.

Mixed cyclic phenol sulfides, and charge control agents and toners using the same

The present invention discloses an oxidized mixed cyclic phenol sulfide which is a mixture of the oxidized cyclic phenol sulfide wherein m is 8 and the oxidized cyclic phenol sulfide wherein m is an integer other than 8, the oxidized cyclic phenol sulfide being represented by the following formula (1): wherein R is a straight or branched alkyl group having 1 to 6 carbon atoms, m is an integer from 4 to 9, and n is 1 or 2; or an oxidized cyclic phenol sulfide of formula (1) wherein m is 8. The present invention also discloses a charge control agent which comprises the above sulfide(s) as the active ingredient; and a toner which comprises the charge control agent, a coloring agent and a binder resin. This charge control agent is particularly useful for color toners, and it speeds up charging risetime, and has a high charge amount and charging characteristics excellent in environmental stability. Further, the charge control agent is safe since it does not have any problem with the waste regulations.

Oxidized mixed cyclic phenol sulfides, and charge control agents and toners using the same

The present invention is to provide a charge controlling agent and negatively chargeable toner that do not contain any toxic metal, are essentially free from the risk of evoking ignition or explosion, and can exhibit a high charge amount and rapid initial increase in charging. The charge controlling agent is a mono azo iron complex compound represented by Formula (1): wherein J represents H, alkali metal, ammonium, or alkyl ammonium, or two or more of those elements in combination.

Mono azo iron complex compound, and charge controlling agent and toner using the same

An electrophotographic printing method which comprises using a charge controlling agent containing a monoazo iron complex compound of the formula (1) as an effective component, wherein A, A, Band Bare respectively independently H, an alkyl group or a halogen atom, J is H, an alkali metal, NHor an alkylammonium, they may be two or more kinds, Xand Xare respectively independently H, an alkyl group or a halogen atom, and Yand Yare respectively independently H, an alkyl group or an aromatic group which may have a substituent, provided that a case in which A, A, B, B, X, X, Y, and Yare hydrogen at the same time is excluded.

Electrophotographic printing method, monoazo iron complex compound, charge controlling agent using the same and toner using the charge controlling agent

Organic metal complex compound and electrostatic image developing toner using the same

An electrophotographic photoconductor is composed of an electroconductive substrate and a photoconductive layer formed thereon including a diamine compound of formula (I): ##STR1## wherein R.sup.1 represents an alkyl group having 1 to 4 carbon atoms, or an aryl group; R.sup.2 represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an alkoxyl group having 1 to 4 carbon atoms; n is an integer of 1 to 3; and ##STR2## represents an arylene group or a bivalent group of a heterocyclic compound. A diamine compound for use in the electrophotographic photoconductor is also disclosed.

Electrophotographic photoconductor and diamine compounds for use in the

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Koriyama, Japan

Masaki Okubo