Konishiroku Photo Industry Co., Ltd.

Konica Corporation

Kiyoshi Sawada

Akira Kinoshita

Osamu Sasaki

Satoshi Goto

Naohiro Hirose

Takahiro Mori

Tawara Komamura

Jiro Takahashi

Ryosuke Isobe

Kunitsuna Sasaki

Yuki Ando

Akihiko Itami

Shinichi Suzuki

Kazumasa Watanabe

Yoshiaki Takei

Yoshihide Fujimaki

Takayuki Sugaiwa

Ssamu Sasaki

Kazumasa Watanable

A magnetic recording medium is disclosed which comprises a non-magnetic support and a magnetic layer comprising a ferromagnetic powder having a specific surface area of not less than 55 m.sup.2 /g and at least two kinds of resins each containing repetitive units having a polar group selected from the group consisting of a --SO.sub.3 M group, a --OSO.sub.3 M group, a --COOM group and a --PO(OM').sub.2 group, wherein M is a hydrogen atom or an alkali metal atom, and M' is a hydrogen atom, an alkali metal atom or an alkyl group, and the glass transition points of said two resins are different not less than 60.degree. C. from each other. The recording medium is improved in the dispersibility of the ferromagnetic powder in the magnetic layer and has a satisfactory surface smoothness, high electromagnetic conversion characteristics and a satisfactory running durability.

Magnetic recording medium comprising ferromagnetic powder and polar

A magnetic recording medium is disclosed which has a magnetic layer comprising a ferromagnetic powder and a specific polyurethane resin as a binder. The polyurethane resin has a weight average molecular weight of not more than 30,000, a glass transition point of not higher than 0.degree. C. and a -SO.sub.3 M group, wherein M is a hydrogen atom or an alkali metal atom, in an amount of not less than 0.35% by weight in terms of sulfur atom. The recording medium is excellent in the dispersibility of the magnetic powder in the binder and has high running stability.

Magnetic recording medium comprising a polyurethane binder resin having

There is disclosed the method of preparing a magnetic recording medium having an improved running durability and the excellent electromagnetic conversion characteristics, wherein the magnetic paint for a magnetic layer is prepared by the steps of:

Production method for magnetic recording medium

An electrophotographic photoreceptor containing titanyl phthalocyanine that has a maximum intensity peak of the Bragg angle 2.theta. at 27.3.degree..+-.0.2.degree. with respect to characteristic X-rays of Cu K.alpha. at a wavelength of 1.541.ANG. and which has a maximum intensity peak of 6.8.degree..+-.0.2.degree. in the 2.theta. range of 6.degree.-8.degree. is disclosed.

Electrophotographic photoreceptor

The present invention relates to an electrophotographic photoreceptor containing titanyl phthalocyanine in a crystalline state that has a maximum intensity peak of the Bragg angle 2.theta. at 27.2.degree..+-.0.2.degree. crystal planes corresponding to diffraction lines at 9.6.degree..+-.0.2.degree., 11.7.degree..+-.0.2.degree. and 24.2.degree..+-.0.2.degree. in a diffraction spectrum obtained with characteristic X-rays of Cu K.alpha. at a wavelength of 1.541 .ANG., and that also has an aggregated state such that a visible and near infrared absorption spectrum has a maximum absorption in the range of 780-860 nm, said photoreceptor further containing an ethylene copolymer resin and/or a polyamide resin in an intermediate layer provided between a light-sensitive layer and an electroconductive layer or an electroconductive substrate.

Electrophotographic photoreceptor using titanyl phthalocyanine

Disclosed is a photoreceptor for electrophotography comprising a conductive support and a subbing layer thereon made of a hydroxystyrene polymer or copolymer. A photosensitive layer is formed on the subbing layer and may comprise a carrier generator layer and transport layer. Optionally, a surface protective layer may be present.

Photoreceptor for electrophotography having a hydroxystyrene subbing

An electrophotographic photosensitive member having a photesensitive layer containing an azo compound represented by the following Formula [I],

Electrophotographic photoreceptor with azo-containing photosensitive

A photoreceptor is disclosed which comprises a photosensitive layer and an electrically conductive support. Said photosensitive layer contains a carrier generation material and a carrier transport material, said carrier generation material being a trisazo compound of the present invention, or said photosensitive layer may consist of a carrier generation layer containing said trisazo compound and a carrier transport layer containing said carrier transport material with or without an intermediate layer being provided between said support and said photosensitive layer.

Photoreceptor containing a trisazo compound for use in electrophotography

Photoreceptor for electrophotography comprising a conductive support and an overlaying photosensitive layer thereon, said photosensitive layer containing at least one azo compound of Formula I or II ##STR1## wherein Ar.sub.1, Ar.sub.2, Ar.sub.3 and Ar.sub.4 each is an aromatic hydrocarbon ring radical or an aromatic heterocyclic ring radical; R.sub.1, R.sub.2, R.sub.3 and R.sub.4 each is an electron attractive group or hydrogen provided that at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is an electron attractive group; and A is ##STR2## wherein X is a hydroxy group or a group represented by the formula: ##STR3## wherein R.sub.6 and R.sub.7 each is hydrogen or an alkyl group, and R.sub.8 is an alkyl or aryl group; Y is halogen, an alkyl or alkoxy group, a carboxy group, a sulfo group, a carbamoyl or sulfamoyl group; Z is an atomic group necessary for making an aromatic hydrocarbon ring or an aromatic heterocyclic ring; R.sub.5 is hydrogen, an amino or carbamoyl group, a carboxy group or an ester group thereof; Ar.sub.5 is an aryl group; n is an integer of 1, 2 or 3; and m is an integer of 0, 1 or 2.

Disazo photoreceptors for electrophotography

An electrophotographic photosensitive member, comprising an electroconductive support and, provided thereon, a photosensitive layer containing a bisazo compound represented by the formula [I]: ##STR1## wherein A is as per defined in the specification. The electrophotographic photosensitive member according to the present invention is stable to heat and light and also excellent in carrier generating ability.

Electrophotographic bisazo photosensitive member

An electrophotograhic photoreceptor that has great ability to generate carriers and which has high sensitivity but low residual potential is disclosed. This photoreceptor is characterized by having formed on an electrically conductive support a light-sensitive layer containing a bisazo compound of the following formula: ##STR1## (wherein R.sub.1 is a cyano group, a chlorine atom or a bromine atom; X.sub.1 is a halogen atom, an alkyl group, an alkoxy group or a cyano group; X.sub.2 is a hydrogen atom, a halogen atom, an alkyl atom or an alkoxy group; A is ##STR2## wherein Y is a substituted or unsubstituted carbamoyl group or a substituted or unsubstituted sulfamoyl group; Z is an atomic group necessary for forming a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted heteroaromatic ring; R.sub.2 is a hydrogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted carbamoyl group, a carboxy group or an ester group thereof; and A' is a substituted or unsubstituted aryl group).

Electrophotographic substituted p,p'-bisazo diphenyl acrylonitrile

Disclosed is an electrophotographic photoreceptor which comprises, on an electroconductive support, a light sensitive layer containing a carrier generation material, a carrier transport material consisting of a carbazole derivative represented by the following general formula I: ##STR1## where R.sub.1, R.sub.2, R.sub.3, R.sub.4 and Ar are as defined in the specification.

An electrophotographic photoreceptor having formed on an electrically conductive support a light-sensitive layer containing a hydrazone derivative of formula (I) as a photoconductive material is disclosed: ##STR1## wherein Z is a divalent hydrocarbon group necessary to form in conjunction with a nitrogen atom a 5- or 6-membered nitrogen-containing heterocyclic ring condensed to the benzene ring; R.sub.1 is an aryl group or a heterocyclic group; R.sub.2 is a hydrogen atom, an alkyl group or an aryl group; X is a hydrogen atom, a halogen atom, an alkyl group, a substituted amino group, an alkoxy group or a cyano group; and n is an integer of 0 or 1. This hydrazone derivative exhibits great carrier transporting ability when it is incorporated in the light-sensitive layer.

Electrophotographic photoreceptor with hydrazone derivative

There is disclosed an electrophotosensitive receptor which comprises a conductive support and an electrophotosensitive layer which comprises a carrier transporting material and a specified trisazo compound wherein the azo compound is applied as a coating solution containing a solvent or as a liquid dispersion mixture containing a dispersion medium. Alternatively, the electrophotosensitive receptor comprises a conductive support and an electrophotosensitive layer which comprises said azo compound wherein the azo compound is applied as a coating solution containing a solvent and a binder or as a liquid dispersion medium containing a dispersion medium and a binder.

Electrophotosensitive receptor with trisazo compound

Electrophotographic light-sensitive elements containing substituted or unsubstituted fluorenone hydrazones as charge generating or charge transport materials are described.

Growing community of inventors

Hino, Japan

Kiyoshi Sawada