| CPC C09K 19/2007 (2013.01) [G02F 1/133541 (2021.01); G02F 1/133553 (2013.01); G02F 1/13363 (2013.01); G02F 1/133788 (2013.01); G02F 1/13718 (2013.01); C09K 2019/2078 (2013.01)] | 12 Claims |

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1. A method for producing a cholesteric liquid crystal layer, comprising:
a step X of forming a cholesteric liquid crystal layer A that satisfies all of conditions 1 to 3 and in which a liquid crystal compound is aligned into a state of a cholesteric liquid crystalline phase; and
a step Y of carrying out a treatment to increase a helical pitch of the cholesteric liquid crystalline phase in the cholesteric liquid crystal layer A obtained by the step X to increase a tilt angle of an arrangement direction of bright portion and dark portion derived from the cholesteric liquid crystalline phase, as observed in a cross-section perpendicular to a main surface of the cholesteric liquid crystal layer A, with respect to a normal direction of the main surface of the cholesteric liquid crystal layer A,
condition 1: the cholesteric liquid crystal layer A has a liquid crystal alignment pattern in which a direction of a molecular axis derived from the liquid crystal compound changes while continuously rotating along at least one in-plane direction,
condition 2: the molecular axis of the liquid crystal compound is tilted with respect to the main surface of the cholesteric liquid crystal layer A on both main surfaces of the cholesteric liquid crystal layer A,
condition 3: the arrangement direction of bright portion and dark portion derived from the cholesteric liquid crystalline phase is tilted with respect to a normal line of the main surface of the cholesteric liquid crystal layer A, in the cross-section perpendicular to the main surface of the cholesteric liquid crystal layer A observed by a scanning electron microscope.
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