Patents by Inventor Atsushi Iwasa
Atsushi Iwasa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20180079920Abstract: Provided are a dispersion of colored resin fine particles for an aqueous ink which has property of improving a drying property of the drawn lines in addition to the performances of a colorant such as a color developability, a weather resistance, and stability, and an aqueous ink composition for a writing instrument which is prepared by using the dispersion. The dispersion is characterized by comprising at least a vinyl monomer (A) containing an acidic functional group of a carboxyl group having solubility of 10% by mass or lower in water, an ester monomer (B) of acrylic acid or methacrylic acid with linear or cyclic alcohol having 2 to 18 carbon atoms, and a basic dye or an oil-soluble dye are dispersed in water. Also, the aqueous ink composition for a writing instrument is characterized by containing the dispersion, a water-soluble organic solvent and water.Type: ApplicationFiled: March 31, 2016Publication date: March 22, 2018Applicant: MITSUBISHI PENCIL COMPANY, LIMITEDInventors: Hisato Haga, Atsushi Iwasa
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Publication number: 20120316276Abstract: An aqueous marking ink composition that contains at least 1 to 20% by mass of a resin which is water-soluble and has a hydrophobic part in a molecule thereof, a colorant containing at least 5 to 30% by mass of titanium oxide, 0.05 to 2% by mass of at least one selected from acetylene glycols, acetylene alcohols or derivatives thereof, 1 to 20% by mass of a water-soluble solvent having a vapor pressure of 5 mmHg or less at 25° C. and water. The composition can provide good wetting property to a non-absorbing surface of metals, resins and the like stained with oils, can write smoothly thereon at a low viscosity without being repelled to make it possible to obtain drawn lines having a high masking property and a high fixing property, and is readily redispersed by a simple stirring operation.Type: ApplicationFiled: December 16, 2010Publication date: December 13, 2012Applicant: Mitsubishi Pencil Company, LimitedInventors: Atsushi Iwasa, Yoko Toi, Yoshihito Fujiwara
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Patent number: 7837404Abstract: An applicator which includes a rear barrel 1; an ink occlusion element 10 accommodated in rear barrel 1; an ink occlusion element receiver 20 opposing the front end part of ink occlusion element 10; a see-through front barrel 30 fitted to the opening of rear barrel 1, a detection tube 40 inserted in front barrel 30 for flowing ink from ink occlusion element 10; a joint core 50 supported by detection tube 40 and flowing out ink from ink occlusion element 10; and a pen core 60 supported by detection tube 40 and disposed on the opposite side of joint core 50 with a detection space 63 from joint core 50. Detection tube 40, joint core 50 and pen core 60 are formed into an integral structure. It is possible to exactly grasp the ink end state in a visual manner, based on the presence/absence of ink in detection space 63 of detection tube 40.Type: GrantFiled: August 13, 2004Date of Patent: November 23, 2010Assignee: Mitsubishi Pencil Co., Ltd.Inventors: Atsushi Iwasa, Yukinori Sawa, Akira Fukai, Takahiro Osada
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Publication number: 20080193197Abstract: An applicator which includes a rear barrel 1; an ink occlusion element 10 accommodated in rear barrel 1; an ink occlusion element receiver 20 opposing the front end part of ink occlusion element 10; a see-through front barrel 30 fitted to the opening of rear barrel 1, a detection tube 40 inserted in front barrel 30 for flowing ink from ink occlusion element 10; a joint core 50 supported by detection tube 40 and flowing out ink from ink occlusion element 10; and a pen core 60 supported by detection tube 40 and disposed on the opposite side of joint core 50 with a detection space 63 from joint core 50. Detection tube 40, joint core 50 and pen core 60 are formed into an integral structure. It is possible to exactly grasp the ink end state in a visual manner, based on the presence/absence of ink in detection space 63 of detection tube 40.Type: ApplicationFiled: August 13, 2004Publication date: August 14, 2008Applicant: Mitsubishi Pencil Co., Ltd.Inventors: Atsushi Iwasa, Yukinori Sawa, Akira Fukai, Takahiro Osada
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Patent number: 6517273Abstract: A free-ink type writing instrument having a temporary ink collector having a sectionally combed configuration, between an ink tank chamber and an writing tip and inside the front barrel, wherein all or part of the gaps between neighboring combed teeth for retaining ink in the temporary ink collector are set equal to 0.15 mm or smaller, and the ink tank is charged with an ink having a surface tension equal to 30 mN/m or lower at 25° C.Type: GrantFiled: December 11, 2001Date of Patent: February 11, 2003Assignee: Mitsubishi Pencil Kabushiki KaishaInventors: Takao Koyama, Kazuhisa Kirita, Atsushi Iwasa
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Publication number: 20020131808Abstract: A free-ink type writing instrument includes: an ink tank for holding ink; a temporary ink collector for temporarily retaining the ink flowing out from the ink tank; a partitioning wall separating the ink tank and the temporary ink collector; and a pen core disposed from the ink tank, penetrating through the partitioning wall and the ink collector so as to allow ink to flow out from the ink tank, and is characterized in that the storage volume Vc of the ink collector and the ink tank volume Vo satisfy the relation Vc≧0.18Vo.Type: ApplicationFiled: December 11, 2001Publication date: September 19, 2002Inventors: Takao Koyama, Kazuhisa Kirita, Atsushi Iwasa
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Patent number: 6443649Abstract: A free-ink type writing instrument includes: an ink tank for holding ink; a temporary ink collector for temporarily retaining the ink flowing out from the ink tank; a partitioning wall separating the ink tank and the temporary ink collector; and a pen core disposed from the ink tank, penetrating through the partitioning wall and the ink collector so as to allow ink to flow out from the ink tank, and is characterized in that the storage volume Vc of the ink collector and the ink tank volume Vo satisfy the relation Vc≧0.18 Vo.Type: GrantFiled: December 11, 2001Date of Patent: September 3, 2002Assignee: Mitsubishi Pencil Kabushiki KaishaInventors: Takao Koyama, Kazuhisa Kirita, Atsushi Iwasa
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Publication number: 20020081142Abstract: A free-ink type writing instrument having a temporary ink collector having a sectionally combed configuration, between an ink tank chamber and an writing tip and inside the front barrel, wherein all or part of the gaps between neighboring combed teeth for retaining ink in the temporary ink collector are set equal to 0.15 mm or smaller, and the ink tank is charged with an ink having a surface tension equal to 30 mN/m or lower at 25° C.Type: ApplicationFiled: December 11, 2001Publication date: June 27, 2002Inventors: Takao Koyama, Kazuhisa Kirita, Atsushi Iwasa
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Patent number: 5965634Abstract: Provided is a stable water base ink composition which has a sufficiently high concentration as ink for an ink jet-recording apparatus and writing instruments and prevents the recorded images and the written characters from being blurred or disappearing with water and sweat and which has such an excellent light fastness that the images and the characters do not deteriorate over a long period of time and does not cause a change in physical properties and precipitates. A water base dispersion liquid containing colored resin fine particles is prepared by emulsion-polymerizing a vinyl monomer in the presence of a hydrophobic dye and then diluted with water or a water soluble organic solvent, whereby the water base ink composition is produced.Type: GrantFiled: June 10, 1997Date of Patent: October 12, 1999Assignee: Mitsubishi Pencil Kabushiki KaishaInventors: Hiroyuki Idogawa, Yasuaki Ogiwara, Atsushi Iwasa, Kiyokazu Sakurai
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Patent number: 5959000Abstract: Provided is an erasable ink comprising an emulsion liquid prepared by polymerizing a polymerizable monomer containing a conjugate diene compound in a solvent containing water in the presence of a dye and a surfactant, wherein the polymerizable monomer may contain a vinyl compound as well as a conjugate diene compound, and used are 0.01 to 100 parts by weight of the dye and 0.1 to 30 parts by weight of the surfactant each per 100 parts by weight of the polymerizable monomer.Type: GrantFiled: May 1, 1997Date of Patent: September 28, 1999Assignee: Mitsubishi Pencil Kabushiki KaishaInventors: Yasuaki Ogiwara, Kiyokazu Sakurai, Atsushi Iwasa
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Patent number: 5942560Abstract: Provided is a colored resin fine particle water base dispersion liquid which can be a base material for an ink causing no precipitates and having storage stability. Further provided is a water base ink composition for an ink jet recording apparatus or a water base ink composition for a writing tool capable of providing recorded images or written characters and drawn lines which are clear and neither are blurred nor disappear due to water and sweat and which are so excellent in light fastness that they are not deteriorated over a long period of time, wherein the colored resin fine particle water base dispersion liquid is produced by mixing a water soluble basic dye with a mixed vinyl monomer containing a vinyl monomer having an acid functional group and emulsion-copolymerizing the above mixture.Type: GrantFiled: August 6, 1997Date of Patent: August 24, 1999Assignee: Mitsubishi Pencil Kabushiki KaishaInventors: Hiroyuki Idogawa, Yasuaki Ogiwara, Atsushi Iwasa, Kiyokazu Sakurai