	US 12,403,712 B2
	Heat-sensitive recording material
Shinya Akimoto, Tokyo (JP); Kentaro Morofuji, Tokyo (JP); and Takashi Takemura, Tokyo (JP)
Assigned to OJI HOLDINGS CORPORATION, Tokyo (JP)
Appl. No. 17/919,887
Filed by OJI HOLDINGS CORPORATION, Tokyo (JP)
PCT Filed Apr. 21, 2021, PCT No. PCT/JP2021/016171 § 371(c)(1), (2) Date May 19, 2023, PCT Pub. No. WO2021/215470, PCT Pub. Date Oct. 28, 2021.
Claims priority of application No. 2020-076838 (JP), filed on Apr. 23, 2020; and application No. 2020-197667 (JP), filed on Nov. 27, 2020.
Prior Publication US 2023/0271444 A1, Aug. 31, 2023
Int. Cl. B41M 5/44 (2006.01); B41M 5/323 (2006.01); B41M 5/333 (2006.01); B41M 5/42 (2006.01)

CPC B41M 5/44 (2013.01) [B41M 5/323 (2013.01); B41M 5/3336 (2013.01); B41M 5/426 (2013.01); B41M 2205/04 (2013.01); B41M 2205/38 (2013.01)]

13 Claims

1. A heat-sensitive recording material comprising:

an undercoat layer formed on one surface of a support; and

a heat-sensitive recording layer formed on the undercoat layer, wherein

the heat-sensitive recording layer contains a leuco dye and a coloring agent,

the undercoat layer contains hollow particles and a binding resin,

a maximum particle diameter of the hollow particles is 10 to 30 μm,

a particle diameter of the hollow particles at cumulative 50 volume % is 4.0 to 15 μm,

a ratio D100/D50 is 1.8 to 3.0, D100 representing the maximum particle diameter of the hollow particles, and D50 representing the particle diameter of the hollow particles at cumulative 50 volume %,

a volume percentage of the hollow particles having particle diameters of 2.0 μm or less is 1% or less, and

a content of the hollow particles with respect to a total solids content of the undercoat layer is 5 to 40 mass %.