# US 2021/0241786 A1 · Magnetic tape cartridge and magnetic tape apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0241786 A1 - Document ID: US20210241786A1 - Status: Published application - Kind: A1 - Application number: 17/160,534 - Filed: 2021-01-28 - Published: 2021-08-05 - Earliest claimed: 2020-01-31 - Assignees: FUJIFILM Corporation - Applicants: FUJIFILM Corporation - Inventors: Norihito KASADA; Yosuke Sumiya - Web page: https://patentgrep.com/patent/US20210241786A1 ## CPC - G11B 5/00813: {magnetic tapes} - G11B 5/7356: {comprising non-magnetic particles in the back layer, e.g. particles of TiO2, ZnO or SiO2} - G11B 5/70678: {Ferrites} - G11B 5/733: characterised by the addition of non-magnetic particles {(base layers having a non-magnetic layer under a soft magnetic layer G11B5/736; magnetic recording media substrates G11B5/739)} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract The magnetic tape cartridge includes a magnetic tape that is accommodated in the magnetic tape cartridge while being wound around a reel hub. The magnetic tape has a non-magnetic support and a magnetic layer including ferromagnetic powder, and includes one or more components selected from the group consisting of a fatty acid and a fatty acid amide in a portion on the magnetic layer side on the non-magnetic support, and after the magnetic tape cartridge is stored in an environment of an atmosphere temperature of 60° C. and a relative humidity of 80% for 24 hours, a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed at a photoelectron take-off angle of 10 degrees on a surface of the magnetic layer in an inner region during winding of the magnetic tape is 45 at % or more. ## Claims ### Claim 1 A magnetic tape cartridge comprising: a magnetic tape that is accommodated in the magnetic tape cartridge while being wound around a reel hub, wherein the magnetic tape has a non-magnetic support and a magnetic layer including ferromagnetic powder, and includes one or more components selected from the group consisting of a fatty acid and a fatty acid amide in a portion on the magnetic layer side on the non-magnetic support, and after the magnetic tape cartridge is stored in an environment of an atmosphere temperature of 60° C. and a relative humidity of 80% for 24 hours, a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed at a photoelectron take-off angle of 10 degrees on a surface of the magnetic layer in an inner region during winding of the magnetic tape is 45 at % or more. ### Claim 2 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the C—H derived C concentration is 45 at % or more and 80 at % or less. ### Claim 3 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the magnetic layer includes an inorganic oxide-based particle. ### Claim 4 (depends on 3) The magnetic tape cartridge according to claim 3, wherein the inorganic oxide-based particle is a composite particle of an inorganic oxide and a polymer. ### Claim 5 (depends on 1) The magnetic tape cartridge according to claim 1, wherein a material constituting at least an outer peripheral surface layer portion of the reel hub has a flexural modulus of 5 GPa or more. ### Claim 6 (depends on 5) The magnetic tape cartridge according to claim 5, wherein the flexural modulus is 8 GPa or more. ### Claim 7 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the magnetic tape has a non-magnetic layer including non-magnetic powder between the non-magnetic support and the magnetic layer. ### Claim 8 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the magnetic tape has a back coating layer including non-magnetic powder on a surface side of the non-magnetic support opposite to a surface side provided with the magnetic layer. ### Claim 9 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the ferromagnetic powder is hexagonal barium ferrite powder. ### Claim 10 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the ferromagnetic powder is hexagonal strontium ferrite powder. ### Claim 11 (depends on 1) The magnetic tape cartridge according to claim 1, wherein the ferromagnetic powder is ε-iron oxide powder. ### Claim 12 (depends on 1) A magnetic tape apparatus comprising: the magnetic tape cartridge according to claim 1. ### Claim 13 (depends on 12) The magnetic tape apparatus according to claim 12, wherein the C—H derived C concentration is 45 at % or more and 80 at % or less. ### Claim 14 (depends on 12) The magnetic tape apparatus according to claim 12, wherein the magnetic layer includes an inorganic oxide-based particle. ### Claim 15 (depends on 14) The magnetic tape apparatus according to claim 14, wherein the inorganic oxide-based particle is a composite particle of an inorganic oxide and a polymer. ### Claim 16 (depends on 12) The magnetic tape apparatus according to claim 12, wherein a material constituting at least an outer peripheral surface layer portion of the reel hub has a flexural modulus of 5 GPa or more. ### Claim 17 (depends on 16) The magnetic tape apparatus according to claim 16, wherein the flexural modulus is 8 GPa or more. ### Claim 18 (depends on 12) The magnetic tape apparatus according to claim 12, wherein the magnetic tape has a non-magnetic layer including non-magnetic powder between the non-magnetic support and the magnetic layer. ### Claim 19 (depends on 12) The magnetic tape apparatus according to claim 12, wherein the magnetic tape has a back coating layer including non-magnetic powder on a surface side of the non-magnetic support opposite to a surface side provided with the magnetic layer.