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Author

Fujiwara Naoki

Bio: Fujiwara Naoki is an academic researcher. The author has contributed to research in topics: Vinyl alcohol & Polyvinyl alcohol. The author has an hindex of 9, co-authored 103 publications receiving 526 citations.


Papers
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Patent
19 Mar 1996
TL;DR: In this article, a thermal recording material is constituted by providing a vinyl alcohol type polymer with syndiotacticity of 55% or more in a thermal color forming layer, which is used as a dispersant to disperse the thermal dye or the coupler allowing the dye to form a color at the time of heating in an aq. medium.
Abstract: PURPOSE: To obtain not only a thermal recording material not having the background color of a support base material and capable of obtaining a sharp image even at the time of high speed printing but also an excellent dispersant by providing a vinyl alcohol type polymer of which the syndiotacticity is a specific ratio or more in a thermal color forming layer. CONSTITUTION: A thermal recording material is constituted by providing a vinyl alcohol type polymer with syndiotacticity of 55% or more in a thermal color forming layer. In this case, the vinyl alcohol type polymer contains 2-8mol% of an ionic group. By using this vinyl alcohol type polymer, a dispersant for a thermal dye or a coupler allowing the dye to form a color at the time of heating is constituted. The vinyl alcohol type polymer is used as a dispersant to disperse the thermal dye or the coupler allowing the dye to form a color at the time of heating in an aq. medium to prepare an aq. dispersion. By this constitution, a thermal recording material not having the background color of a support base material capable of obtaining a sharp image even at the time of high speed printing is obtained.

70 citations

Patent
16 Sep 1997
TL;DR: In this paper, a heat-sensitive recording material, which is excellent in the preserving properties of a developed color portion, in which the color of base material is not recognized, is provided on the surface of a base material.
Abstract: PROBLEM TO BE SOLVED: To provide a heat-sensitive recording material, which is excellent in the preserving properties of a developed color portion, in which the color of base material is not recognized, which has so excellent color developing sensitivity as to fully allow to cope with high speed printing and further a coating layer, by employing with which a little wear of a heat-sensitive head results. SOLUTION: In this heat-sensitive recording material, a coating layer prepared by blending 0.003-1 pts.wt. alkali metal ion B to 100 pts.wt. modified polyvinyl alcohol A containing 3-15mol.% ethylene unit is provided on the surface of a base material. Since the modified PVA used is suitable for the binder for a heat-sensitive developed color layer, a surface protective layer and a bottom layer, this heat-sensitive recording material is excellent in preserving properties such as color developing sensitivity, water resistance, oil resistance, plasticizer resistance and resistance to poly vinyl chloride film. Further, since this heat- sensitive recording material is excellent in high speed printing properties and the resolution of an image, this heat-sensitive recording material is suitably used in a field, in which high speed printing such as a facsimile or the like is necessary.

47 citations

Patent
11 Nov 2004
TL;DR: In this paper, the problem of providing a thermosensitive recording material, the color developability of the printing part of which is favorable, in the non-printing part in which fogging (coloring of a ground part) develops hardly, which has very excellent water resistance, resistance to lubricant and resistance to plasticizer.
Abstract: PROBLEM TO BE SOLVED: To provide a thermosensitive recording material, the color developability of the printing part of which is favorable, in the non-printing part of which fogging (coloring of a ground part) develops hardly, which has very excellent water resistance, resistance to lubricant and resistance to plasticizer since just after manufacturing even under the condition that a layer made of PVA is dried in low temperature ranging from room temperature up to about 50°C. SOLUTION: This thermosensitive recording material has a specified silicic structural unit and, at the same time, includes a composition consisting of a 1-20 mol% of ethylene unit-containing vinyl alcohol-base polymer (A), a zirconium compound (B) and/or colloidal silica (C). COPYRIGHT: (C)2005,JPO&NCIPI

36 citations

Patent
07 Nov 2000
TL;DR: In this paper, the content of carboxyl groups and lactone rings of a vinyl alcohol-based polymer has been shown to have a composition excellent in thermal stability, waterproof, a barrier property against gas or steam, low temperature leaving stability in an aqueous solution and biodegradability.
Abstract: PROBLEM TO BE SOLVED: To obtain a vinyl alcohol-based polymer capable of imparting a composition excellent in thermal stability, waterproof, a barrier property against gas or steam, low temperature leaving stability in an aqueous solution and biodegradability by specifying the content of ethylenic units or the like SOLUTION: This polymer has an ethylenic unit content of 2-19 mol%, a polymerization degree of 200-2,000, a saponification degree of 809999% and a total content of carboxyl groups and lactone rings of 002-04% The total content of carboxyl groups and lactone rings preferably meets the formula (wherein P is a viscosity average polymerization degree of the vinyl alcohol- based polymer), it is especially preferable that the content of 1,2-glycol bonds is 12-2%, the molar fraction of central hydroxyl groups in a hydroxyl group triplet shown by triad designation to vinyl alcohol units is 65-98% and the melting point is 160-230 degC

31 citations

Patent
10 Feb 1997
TL;DR: In this article, an epoxidized polymer of at least one member selected from among vinyl monomers, diene monomers and oxyalkylene monomers is reacted with a polymer having a thiol group (optionally protected) or a thioester group at one end only.
Abstract: PROBLEM TO BE SOLVED: To facilitate the production of a polymer comprising a combination of various polymers (graft, block, branched, and three-dimensionally crosslinked polymers) which is unobtainable by any conventional technique for copolymerization SOLUTION: An epoxidized polymer of at least one member selected from among vinyl monomers, diene monomers, and oxyalkylene monomers is reacted with a polymer having a thiol group (optionally protected) or a thioester group at one end only

22 citations


Cited by
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Patent
02 Oct 2006
TL;DR: An ink-jet recording medium having a support and, provided thereon, at least one ink receiving layer containing polymeric organic particles, characterized in that said organic particles have a glass transition temperature of 40 °C or higher, and are amphoteric polymeric organics having both functional groups of cationic groups and anionic groups as discussed by the authors.
Abstract: An ink-jet recording medium having a support and, provided thereon, at least one ink receiving layer containing polymeric organic particles, characterized in that said polymeric organic particles have a glass transition temperature of 40 °C or higher, and are amphoteric polymeric organic particles having both functional groups of cationic groups and anionic groups. The ink-jet recording medium is excellent in ink absorbing property, coloring concentration, gloss, and the resistance to water, light and yellowing, in particular, excellent in ink absorbing property, coloring concentration, gloss, and the resistance to light and yellowing.

308 citations

Patent
28 Aug 2003
TL;DR: In this paper, a thermal recording material comprising a support and, sequentially superimposed thereon, an undercoating layer, which contains a pigment and a binder as main components, and thermal recording layer which contains an achromatic or hypochromic basic colorless dye and a developer capable of reacting with the basic colourless dye to thereby realize color formation as the main components.
Abstract: A thermal recording material comprising a support and, sequentially superimposed thereon, an undercoating layer, which contains a pigment and a binder as main components, and a thermal recording layer, which contains an achromatic or hypochromic basic colorless dye and a developer capable of reacting with the basic colorless dye to thereby realize color formation as main components, wherein the undercoating layer comprises a carboxymethylcellulose exhibiting an etherification degree of 0.55 to 0.75. Causing the undercoating layer to further contain hydroxymethylcellulose is preferred from the viewpoint of high effectiveness.

270 citations

Patent
25 Jan 2001
TL;DR: In this article, an ink-jet recording material comprising an ink receiving layer (A) present near a supporting material which comprises precipitation method silica particles having an average secondary particle diameter of 500 nm or less, or precipitation method gas phase method (GPSM) particles having average secondary particles diameter of 200-500 nm, and poly(vinyl alcohol) in an amount of less than 20 parts by weight relative to 100 parts of the total volume of the at least one type of particles.
Abstract: An ink-jet recording material comprising an ink receiving layer (A) present near a supporting material which comprises precipitation method silica particles having an average secondary particle diameter of 500 nm or less, or precipitation method silica particles having an average secondary particle diameter of 500 nm or less and gas phase method silica particles having an average secondary particle diameter of 500 nm or less, and further comprises poly(vinyl alcohol) in an amount of less than 20 parts by weight relative to 100 parts by weight of the total silica particles in the ink receiving layer (A), and an ink receiving layer (B) being apart form the supporting material which comprises at least one type of particles selected from among those of a gas phase method silica, alumina and an alumina hydrate and poly(vinyl alcohol) in an amount of less than 25 parts by weight relative to 100 parts by weight of the at least one type of particles.

264 citations

Patent
10 Feb 2012
TL;DR: In this paper, the authors proposed a nonaqueous-electrolyte secondary battery consisting of a negative electrode and a positive electrode each capable of occluding/releasing lithium.
Abstract: A subject for the invention is to improve the cycle characteristics of a high-capacity secondary battery containing an active material packed at a high density, by using a particulate active material having a low aspect ratio. The invention relates to a nonaqueous-electrolyte secondary battery comprising a negative electrode and a positive electrode each capable of occluding/releasing lithium, a separator, and a nonaqueous electrolyte solution comprising a nonaqueous solvent and a lithium salt, characterized in that the separator comprises a porous film made of a thermoplastic resin containing an inorganic filler, and at least either of the following is satisfied: the active material contained in the negative electrode is a particulate active material having an aspect ratio of from 1.02 to 3; and the active material contained in the positive electrode is a particulate active material having an aspect ratio of from 1.02 to 2.2.

184 citations

Patent
31 May 1991
TL;DR: In this paper, an engine exhaust system and a method of controlling hydrocarbon emissions are provided. The system and method are based on the use of two catalytic converter chambers, a first chamber containing a catalytic material and a second chamber containing catalyst as well as molecular sieves capable of adsorbing hydrocarbons during engine start-up and of having hydro-carbons desorbed therefrom when the catalysts reach an effective converting temperature.
Abstract: An engine exhaust system and method of controlling hydrocarbon emissions are provided. The system and method are based on the use of two catalytic converter chambers, a first chamber containing a catalytic material and a second chamber containing catalyst as well as molecular sieves capable of adsorbing hydrocarbons during engine start-up and of having hydrocarbons desorbed therefrom when the catalysts reach an effective converting temperature. According to the invention, engine exhaust is selectively conveyed to each of the two converters in a manner such that initially produced hydrocarbon is withheld in the system by the molecular sieves in order to be recycled through the converters and brought into contact with the catalyst after an effective converting temperature has been attained.

135 citations