US 12,234,365 B2
Pigment composition, identification medium, and authenticity determination method
Masashi Aimatsu, Tokyo (JP)
Assigned to ZEON CORPORATION, Tokyo (JP)
Appl. No. 17/629,871
Filed by ZEON CORPORATION, Tokyo (JP)
PCT Filed Jul. 21, 2020, PCT No. PCT/JP2020/028345
§ 371(c)(1), (2) Date Jan. 25, 2022,
PCT Pub. No. WO2021/020248, PCT Pub. Date Feb. 4, 2021.
Claims priority of application No. 2019-140314 (JP), filed on Jul. 30, 2019.
Prior Publication US 2022/0289988 A1, Sep. 15, 2022
Int. Cl. C09D 11/037 (2014.01); B42D 25/364 (2014.01); B42D 25/391 (2014.01); C08F 222/10 (2006.01); C09B 67/02 (2006.01); C09B 67/22 (2006.01); C09B 69/10 (2006.01); C09D 11/101 (2014.01); G07D 7/1205 (2016.01)
CPC C09D 11/037 (2013.01) [B42D 25/364 (2014.10); B42D 25/391 (2014.10); C08F 222/1025 (2020.02); C09B 67/0034 (2013.01); C09B 67/0097 (2013.01); C09B 69/107 (2013.01); C09D 11/101 (2013.01); G07D 7/1205 (2017.05)] 8 Claims
OG exemplary drawing
 
1. A pigment composition comprising a mixture of: a first cholesteric liquid crystal pigment; and a second cholesteric liquid crystal pigment, wherein:
at least one of the first cholesteric liquid crystal pigment and the second cholesteric liquid crystal pigment is in flake form,
an average particle diameter of the flakes is 20 μm or more and 120 μm or less,
the first cholesteric liquid crystal pigment is a pigment having: a center wavelength of a selective reflection band within a wavelength range of 400 nm or more and 800 nm or less; and a selective reflection bandwidth of 150 nm or less;
the second cholesteric liquid crystal pigment is a pigment which has a selective reflection bandwidth of 200 nm or more within a wavelength range of 400 nm or more and 800 nm or less;
the selective reflection band of the first cholesteric liquid crystal pigment and a selective reflection band of the second cholesteric liquid crystal pigment at least partially overlap with each other; and
a containing amount of the first cholesteric liquid crystal pigment relative to a total amount of the first cholesteric liquid crystal pigment and the second cholesteric liquid crystal pigment is more than 30% by weight and 75% by weight or less.