Fuji Photo Film Company, Limited

Fujifilm Corporation

Noriko Inoue

Hiroo Takizawa

Kiyomi Ejiri

Hiroaki Doushita

Noboru Zinbo

To provide a hologram recording method capable of satisfying high sensitivity and at the same time, satisfying high diffraction efficiency, good preservability, low shrinkage percentage, dry processing and multiplex recording properties, a hologram recording method comprises a first step of producing a latent image upon holographic exposure, and a second step of causing a polymerization reaction due to the latent image, to form a interference fringe providing a refractive index modulation, wherein the first and second steps are dry process; particularly, the first step is a step of producing a colored material to form the latent image and the second step is a step of causing the polymerization reaction upon irradiating the colored material with a light having a wavelength different from that of the holographic exposure, to form the interference fringe providing the refractive index modulation.

Hologram recording method and hologram recording material

A hologram recording material is provided and includes at least a sensitizing dye capable of absorbing light having a hologram recording wavelength to generate an excited state thereof, and an interference fringe-recording component capable of recording interference fringes providing a refractive index modulation by an electron transfer or an energy transfer from the excited state, in which the sensitizing dye in the hologram recording material has a molar absorption coefficient within a range of 1 to 10,000 at the hologram recording wavelength.

Hologram recording material, hologram recording method and optical recording medium

Provided is a magnetic recording medium permitting the controlling of backcoat layer transfer to a magnetic layer surface, a reduction in dropout even when employing microgranular magnetic material, as well as good running stability, durability, and storage properties. The magnetic recording medium has a magnetic layer with a ferromagnetic powder and a binder on one surface of a nonmagnetic support and a backcoat layer with a nonmagnetic powder and a binder on the other surface of the nonmagnetic support. The nonmagnetic powder is an acicular particle having a mean particle diameter of 5 to 300 nm, and the backcoat layer includes water-soluble cations in a quantity of 100 ppm or less and water-soluble anions in a quantity of 150 ppm or less.

Magnetic recording medium

A magnetic recording tape comprising: a magnetic layer comprising a ferromagnetic powder and a binder; a nonmagnetic layer; a support; and a back coating layer, in this order, wherein the magnetic layer has a surface lubricant index of from 1.3 to 3.5, the back coating layer comprises titanium oxide, &#x3b1;-iron oxide or a mixture thereof as an inorganic oxide powder and carbon black and further comprises from 10 to 30 parts by weight, based on 100 parts by weight of a total amount of the inorganic oxide powder and the carbon black, of a binder, and the back coating layer has a surface lubricant index of from 1.10 to 3.0.

Magnetic recording tape

A magnetic recording tape comprising a magnetic layer, a flexible support and a backcoating layer in this order, wherein the backcoating layer has on its surface 10 to 200 projections having a height of 50 to 100 nm per 90 &mgr;m side square as measured with an atomic force microscope and 10 or fewer projections having a height greater than 100 nm and not greater than 500 nm per 90 &mgr;m side square as measured with an atomic force microscope, and the tape has a cupping of 3 to 20% of the tape width with convexity on the magnetic layer side.

A magnetic recording tape comprising a magnetic layer, a flexible support and a backcoating layer in this order, wherein the backcoating layer has on its surface 10 to 200 projections having a height of 50 to 100 nm per 90 &mgr;m side square as measured with an atomic force microscope and 10 or fewer projections having a height greater than 100 nm and not greater than 500 nm per 90 &mgr;m side square as measured with an atomic force microscope, and the tape has a curvature of 3 to 30% of the tape width per meter.

A magnetic recording tape comprising: a magnetic layer comprising a ferromagnetic powder and a binder; a nonmagnetic layer; a support; and a back coating layer, in this order, wherein the magnetic layer comprises, as the binder, a polyurethane resin comprising a dimer diol as a diol component, the back coating layer comprises nonmagnetic inorganic powders and from 1 to 5 parts by weight, based on 100 parts by weight of a total amount of the nonmagnetic inorganic powders, of a lubricant, and a number of protrusions having a height, as measured by an atomic force microscope, of from 30 to 100 nm present on a surface of the back coating layer is from 10 to 1,000 per a 90-&mgr;m square.

A magnetic recording medium comprising: a magnetic layer comprising a ferromagnetic powder and a binder; a non-magnetic support; and a backcoating layer comprising a non-magnetic powder and a binder, in this order, wherein the backcoating layer comprises 0.3 to 5% by weight of at least one of a fatty acid having 10 to 26 carbon atoms and an ester thereof, the backcoating layer has projections having a height of 100 nm or smaller as measured with an atomic force microscope, and a density of projections on the backcoating layer which have a height of 25 to 100 nm as measured with an atomic force microscope is 1000 or fewer per 90 &mgr;m side square.

Growing community of inventors

Kanagawa, Japan

Noriko Inoue