Patents by Inventor Naofumi Kosaka

Naofumi Kosaka 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).

  • Patent number: 12215258
    Abstract: Provided is a PSA sheet having a PSA layer. The PSA layer has a multilayer structure comprising a layer A forming one face of the PSA layer and a layer B placed on the backside of the layer A. The layer B is a photo-crosslinkable PSA layer comprising a photo-crosslinkable polymer.
    Type: Grant
    Filed: July 28, 2020
    Date of Patent: February 4, 2025
    Assignee: NITTO DENKO CORPORATION
    Inventors: Ryoko Asai, Naofumi Kosaka, Yosuke Shimizu
  • Publication number: 20240409788
    Abstract: The present invention provides a pressure-sensitive adhesive composition having an excellent adhesive force when bonding to an adherend, having excellent peelability when subjected to batch heat treatments at a high temperature, and having both a high initial adhesive force and a low post-heating adhesive force. The pressure-sensitive adhesive composition according to the present invention contains: a material having a radically polymerizable functional group; and a thermal polymerization initiator that generates a radical, in which a content of the thermal polymerization initiator is 1.2 to 10 parts by mass with respect to 100 parts by mass of all components excluding the thermal polymerization initiator.
    Type: Application
    Filed: September 21, 2022
    Publication date: December 12, 2024
    Inventors: Satoshi HONDA, Yusuke TAKEDA, Kenta KUMAKURA, Naofumi KOSAKA, Tomokazu TAKAHASHI
  • Publication number: 20240392172
    Abstract: The present invention provides a pressure-sensitive adhesive composition having an excellent pressure-sensitive adhesive force to an adherend even in a high temperature, enabling peeling with a small peel force without any adhesive residue when brought into contact with warm water during peeling, and having a pressure-sensitive adhesive force and easy peelability. The pressure-sensitive adhesive composition according to the present invention contains: an acrylic polymer containing a structural unit of an alkoxy group-containing (meth)acrylate monomer as a main component and containing, with respect to 100 parts by mass of all components of monomer structural units, 1 to 40 parts by mass of a structural unit of a polymerizable monomer having a homopolymer Tg of 0° C. or higher; and a surfactant.
    Type: Application
    Filed: September 21, 2022
    Publication date: November 28, 2024
    Inventors: Yusuke TAKEDA, Satoshi HONDA, Kenta KUMAKURA, Naofumi KOSAKA
  • Publication number: 20240368435
    Abstract: Provided is a PSA sheet having a PSA layer. The PSA layer includes a layer A forming at least one surface thereof. The PSA sheet has an adhesive strength N0 of 2.0 N/10 mm or greater, after one day at room temperature following application of the layer A side to a surface of an alkaline float glass plate as an adherend having a contact angle of 5°-10° with distilled water; has an N1 to N0 reduction rate of 30% or lower, wherein N1 is a water-resistant adhesive strength measured after stored at room temperature for one day, immersed in water for 30 minutes, taken out from the water and then residual water is wiped off, and has an N2 to N0 reduction rate of 40% or higher, wherein N2 is a water-peel strength measured after stored at room temperature for one day, 20 ?L distilled water is dropped onto the adherend and is allowed to enter a PSA layer/adherend interfacial edge. N2 is measured at a tensile speed of 300 mm/min at a peel angle of 180°.
    Type: Application
    Filed: July 15, 2024
    Publication date: November 7, 2024
    Inventors: Naofumi KOSAKA, Yosuke SHIMIZU, Satoshi HONDA, Taiki SHIMOKURI, Shou TAKARADA, Masayuki SATAKE, Kenichi OKADA, Atsushi TAKASHIMA, Ginji MIZUHARA, Masayuki OKAMOTO, Ryoko ASAI
  • Patent number: 12071573
    Abstract: Provided is a PSA sheet having a PSA layer. The PSA layer includes a layer A forming at least one surface thereof. The PSA sheet has an adhesive strength N0 of 2.0 N/10 mm or greater, after one day at room temperature following application of the layer A side to a surface of an alkaline float glass plate as an adherend having a contact angle of 5°-10° with distilled water; has an N1 to N0 reduction rate of 30% or lower, wherein N1 is a water-resistant adhesive strength measured after stored at room temperature for one day, immersed in water for 30 minutes, taken out from the water and then residual water is wiped off, and has an N2 to NO reduction rate of 40% or higher, wherein N2 is a water-peel strength measured after stored at room temperature for one day, 20 ?L distilled water is dropped onto the adherend and is allowed to enter a PSA layer/adherend interfacial edge. N2 is measured at a tensile speed of 300 mm/min at a peel angle of 180°.
    Type: Grant
    Filed: January 28, 2019
    Date of Patent: August 27, 2024
    Assignee: NITTO DENKO CORPORATION
    Inventors: Naofumi Kosaka, Yosuke Shimizu, Satoshi Honda, Taiki Shimokuri, Shou Takarada, Masayuki Satake, Kenichi Okada, Atsushi Takashima, Ginji Mizuhara, Masayuki Okamoto, Ryoko Asai
  • Publication number: 20240269780
    Abstract: A bonding sheet according to the present invention contains a matrix resin; solder particles; and a fluxing agent. In the bonding sheet, the solder particles are dispersed in the matrix resin, and the fluxing agent is unevenly distributed around the solder particles in the matrix resin. The method for producing the bonding sheet of the present invention includes a first step of dissolving a fluxing agent in a first solvent to prepare a fluxing agent solution; a second step of mixing a second solvent, a matrix resin component, solder particles, and the fluxing agent solution to prepare a mixed composition; and a third step of applying the mixed composition onto a substrate to form a coated film, and then drying the coated film to form a bonding sheet.
    Type: Application
    Filed: March 7, 2022
    Publication date: August 15, 2024
    Inventors: Masatoshi KATO, Ayumi NITTA, Naofumi KOSAKA
  • Publication number: 20240139887
    Abstract: A bonding sheet according to the present invention contains a matrix resin; solder particles; and a fluxing agent. The bonding sheet has a surface with a surface roughness Sa of 2.5 ?m or less.
    Type: Application
    Filed: March 7, 2022
    Publication date: May 2, 2024
    Inventors: Ayumi NITTA, Masatoshi KATO, Naofumi KOSAKA
  • Patent number: 11970644
    Abstract: Provided is a method for peeling a PSA sheet adhered on a polarizing plate. The PSA sheet has a PSA layer. The PSA layer includes a layer A forming at least one surface of the PSA layer. Of the polarizing plate, the surface to which the PSA sheet is adhered is corona-treated or plasma-treated. The peeling method includes a water-peel step in which the PSA sheet is peeled from the polarizing plate, in a state where an aqueous liquid exits at the interface between the polarizing plate and the PSA sheet at the front line of peeling the PSA sheet from the polarizing plate, with the aqueous liquid allowed to further enter the interface following the movement of the peel front line.
    Type: Grant
    Filed: January 28, 2019
    Date of Patent: April 30, 2024
    Assignee: NITTO DENKO CORPORATION
    Inventors: Naofumi Kosaka, Yosuke Shimizu, Satoshi Honda, Taiki Shimokuri, Shou Takarada, Masayuki Satake, Kenichi Okada, Atsushi Takashima, Ginji Mizuhara
  • Patent number: 11795350
    Abstract: Provided is an optical PSA composition that can be easily peeled using an aqueous liquid such as water and has sufficient adhesive strength. An optical PSA composition comprising an acrylic polymer is provided. The PSA composition comprises at least one species of compound A selected among surfactants and compounds having polyoxyalkylene backbones. The monomers forming the acrylic polymer comprises less than 20 wt % alkoxyalkyl (meth)acrylate and less than 20 wt % alkoxypolyalkylene glycol (meth)acrylate. Alternatively, the compound A content is less than 1 part by weight to 100 parts by weight of the acrylic polymer.
    Type: Grant
    Filed: July 29, 2019
    Date of Patent: October 24, 2023
    Assignee: NITTO DENKO CORPORATION
    Inventors: Masayuki Okamoto, Naofumi Kosaka, Satoshi Honda, Yosuke Shimizu, Ryoko Asai
  • Publication number: 20230312990
    Abstract: To provide a separation method for a joined object for display device, by which PSA can be peeled off even when the PSA is tightly bonded to a member in the joined object. Provided is a method for separating a joined object for display device. In this method, the joined object comprises two members joined with a PSA comprising a hydrophilicity enhancer. The method comprises a step of peeling the PSA from the member by supplying steam towards the PSA.
    Type: Application
    Filed: July 13, 2021
    Publication date: October 5, 2023
    Applicant: NITTO DENKO CORPORATION
    Inventors: Naofumi KOSAKA, Yosuke SHIMIZU, Kenta KUMAKURA
  • Publication number: 20230144464
    Abstract: Provided is a PSA sheet that can combine bonding reliability and peeling removability, and further can be peeled off without causing deformation or damage to the adherend in various peeling modes. The PSA sheet provided by this invention has a PSA layer. The PSA sheet has a water-peel strength of 2 N/10 mm or less. The PSA sheet further has a stress at 100 % elongation of less than 30 MPa as well as a multiplication product (?f-?f) of fracture stress ?f (MPa) and fracture strain ?f (%) of 250 or greater.
    Type: Application
    Filed: February 24, 2021
    Publication date: May 11, 2023
    Inventors: Yosuke SHIMIZU, Naofumi KOSAKA, Ryoko ASAI, Kenta KUMAKURA
  • Publication number: 20230102613
    Abstract: An adhesive layer (20a) has a creep deformation rate when a stress of 10000 Pa is applied at 50° C. for 1 second is 10% or less, and a creep deformation rate when a stress of 10000 Pa is applied at 50° C. for 30 minutes is 16% or less, in a creep test using a rotational rheometer, and has a 180° peel adhesive strength of 10 mN/20 mm or more with respect to a PMMA film.
    Type: Application
    Filed: February 19, 2021
    Publication date: March 30, 2023
    Applicant: NITTO DENKO CORPORATION
    Inventors: Mizuho MIZUNO, Akiko TANAKA, Naofumi KOSAKA, Kozo NAKAMURA
  • Publication number: 20220282129
    Abstract: Provided is an optical pressure-sensitive adhesive composition that gives a pressure-sensitive adhesive layer having such heating reworkability as to be easily removed from a component such as cover glass at a temperature higher than the service temperature of an image display device. The optical pressure-sensitive adhesive composition of the present invention gives a release force X of 4.0 N/20 mm or less, where the release force X is a release force determined by applying a film to a glass plate through a pressure-sensitive adhesive layer made from the optical pressure-sensitive adhesive composition, and puling the film at a temperature of 100° C., a peel angle of 180 degrees, and a tensile speed of 50 mm/min.
    Type: Application
    Filed: March 7, 2022
    Publication date: September 8, 2022
    Applicant: NITTO DENKO CORPORATION
    Inventors: Shinya YAMAMOTO, Sho TAKARADA, Naofumi KOSAKA, Takahiro NONAKA
  • Publication number: 20220275250
    Abstract: Provided is a photo-crosslinkable PSA comprising a polymer having side-chain benzophenone structures. The photo-crosslinkable PSA is a cured product of a PSA composition comprising an ethylenically unsaturated compound and a benzophenone structure-containing component. The photo-crosslinkable PSA has VOC emissions of 500 ?g/g or less. Also provided is a PSA sheet having a PSA layer formed from the photo-crosslinkable PSA.
    Type: Application
    Filed: July 28, 2020
    Publication date: September 1, 2022
    Inventors: Ryoko ASAI, Naofumi KOSAKA, Yosuke SHIMIZU
  • Publication number: 20220275254
    Abstract: Provided is a PSA sheet having a PSA layer. The PSA layer has a multilayer structure comprising a layer A forming one face of the PSA layer and a layer B placed on the backside of the layer A. The layer B is a photo-crosslinkable PSA layer comprising a photo-crosslinkable polymer.
    Type: Application
    Filed: July 28, 2020
    Publication date: September 1, 2022
    Inventors: Ryoko ASAI, Naofumi KOSAKA, Yosuke SHIMIZU
  • Publication number: 20220169002
    Abstract: The present invention relates to a laminate including a two-dimensional material and an adhesive sheet having a base material and an adhesive layer whose adhesive force decreases due to ultraviolet rays or heat, in which an adhesive force A at 25° C. of the adhesive layer before the ultraviolet rays or heat applies, to a silicon wafer is 1.0 N/20 mm to 20.0 N/20 mm when the adhesive layer is subjected to 180° peeling at a tensile speed of 300 mm/min, and a surface roughness of an adhesive surface of the adhesive layer after the ultraviolet rays or heat has been applied is 0.01 ?m to 8.00 ?m.
    Type: Application
    Filed: February 14, 2020
    Publication date: June 2, 2022
    Inventors: Satoshi HONDA, Naofumi KOSAKA, Shotaro MASUDA, Atsushi YASUI, Hiroki AGO, Kenji KAWAHARA, Shun OYAMA
  • Patent number: 11236254
    Abstract: A separator containing a substrate and a release layer formed on at least one side of the substrate wherein the separator shows a strain of not more than 7% when a load of 5N/20 mm is applied for one minute in the pulling direction, and when the substrate is cut in half in the thickness direction to divide the separator into two, an apparent elastic modulus in the pulling direction of one of the divided separators is larger than an apparent elastic modulus in the pulling direction of the other divided separator.
    Type: Grant
    Filed: October 17, 2017
    Date of Patent: February 1, 2022
    Assignee: NITTO DENKO CORPORATION
    Inventors: Naofumi Kosaka, Keisuke Shimokita, Hironao Ootake, Asami Doi, Mizuho Chiba, Akiko Takahashi
  • Publication number: 20210348036
    Abstract: Provided is an optical PSA composition that can be easily peeled using an aqueous liquid such as water and has sufficient adhesive strength. An optical PSA composition comprising an acrylic polymer is provided. The PSA composition comprises at least one species of compound A selected among surfactants and compounds having polyoxyalkylene backbones. The monomers forming the acrylic polymer comprises less than 20 wt % alkoxyalkyl (meth)acrylate and less than 20 wt % alkoxypolyalkylene glycol (meth)acrylate. Alternatively, the compound A content is less than 1 part by weight to 100 parts by weight of the acrylic polymer.
    Type: Application
    Filed: July 29, 2019
    Publication date: November 11, 2021
    Inventors: Masayuki OKAMOTO, Naofumi KOSAKA, Satoshi HONDA, Yosuke SHIMIZU, Ryoko ASAI
  • Publication number: 20210230455
    Abstract: Provided is a method for peeling a PSA sheet adhered on a polarizing plate. The PSA sheet has a PSA layer. The PSA layer includes a layer A forming at least one surface of the PSA layer. Of the polarizing plate, the surface to which the PSA sheet is adhered is corona-treated or plasma-treated. The peeling method includes a water-peel step in which the PSA sheet is peeled from the polarizing plate, in a state where an aqueous liquid exits at the interface between the polarizing plate and the PSA sheet at the front line of peeling the PSA sheet from the polarizing plate, with the aqueous liquid allowed to further enter the interface following the movement of the peel front line.
    Type: Application
    Filed: January 28, 2019
    Publication date: July 29, 2021
    Inventors: Naofumi KOSAKA, Yosuke SHIMIZU, Satoshi HONDA, Taiki SHIMOKURI, Shou TAKARADA, Masayuki SATAKE, Kenichi OKADA, Atsushi TAKASHIMA, Ginji MIZUHARA
  • Publication number: 20210214587
    Abstract: Provided is a PSA sheet having a PSA layer. The PSA layer includes a layer A forming at least one surface thereof. The PSA sheet has an adhesive strength N0 of 2.0 N/10 mm or greater, after one day at room temperature following application of the layer A side to a surface of an alkaline float glass plate as an adherend having a contact angle of 5°-10° with distilled water; has an N1 to N0 reduction rate of 30% or lower, wherein N1 is a water-resistant adhesive strength measured after stored at room temperature for one day, immersed in water for 30 minutes, taken out from the water and then residual water is wiped off; and has an N2 to N0 reduction rate of 40% or higher, wherein N2 is a water-peel strength measured after stored at room temperature for one day, 20 ?L distilled water is dropped onto the adherend and is allowed to enter a PSA layer/adherend interfacial edge. N2 is measured at a tensile speed of 300 mm/min at a peel angle of 180°.
    Type: Application
    Filed: January 28, 2019
    Publication date: July 15, 2021
    Inventors: Naofumi KOSAKA, Yosuke SHIMIZU, Satoshi HONDA, Taiki SHIMOKURI, Shou TAKARADA, Masayuki SATAKE, Kenichi OKADA, Atsushi TAKASHIMA, Ginji MIZUHARA, Masayuki OKAMOTO, Ryoko ASAI