Infrared-light-transmitting ink of dark color, and infrared-light-reflecting sheet obtained using same

An infrared-light-reflecting sheet comprising an infrared-light-transmitting dark color layer and a transparent resin layer sequentially laminated on a surface of a reflective layer reflecting near infrared light having a wavelength of 750 nm to 1500 nm,

• wherein the infrared-light-transmitting dark color layer contains a main agent resin having a hydroxyl group, a curing agent having an isocyanate group, and a pigment component, a content of the pigment component is 20 parts by mass to 40 parts by mass with respect to 100 parts by mass of a resin component the main agent resin,
• the pigment component contains a brown pigment and a dark color pigment composed of a phthalocyanine pigment, and
• the brown pigment is at least one or more pigments selected from the group consisting of a benzimidazolone pigment, 4-[(2,5-dichlorophenyl)azo]-3-hydroxy-N-(2,5-dimethoxyphenyl)-2-naphthalenecarboxamide, 1-[(4-nitrophenyl)azo]-2-naphthalenol, bis[3-hydroxy-4-(phenylazo)-2-naphthalenecarboxylic acid]copper salt, C. I. Pigment Brown 7, N,N′-bis(2,4-dinitrophenyl)-3,3′-dimethoxy-1,1′-biphenyl-4,4′-diamine, 3,4,9,10-perylenetetracarboxylic diimide, Δ2,2′(1H,1′H)-binaphtho [2,1-b]thiophen-1,1′-dione, and N,N′-(10,15,16,17-tetrahydro-5,10,15,17-tetraoxo)-5H-dinaphtho [2,3-a:
• 2′,3′-i]carbazole-4,9-diyl)bis(benzamide).

An infrared-light-reflecting sheet which is a rear surface protective sheet for a solar cell module, the infrared-light-reflecting sheet being obtained by laminating a plurality of layers, the plurality of layers including at least:

• a transparent adhesion layer transmitting all light beams;
• and
• a reflective layer reflecting near infrared light having a wavelength of 750 nm to 1500 nm,
• wherein two layers among layers laminated between the transparent adhesion layer and the reflective layer are an infrared-light-transmitting dark color layer and a transparent adhesive layer,
• the infrared-light-transmitting dark color layer contains a main agent resin having a hydroxyl group, a curing agent having an isocyanate group, and a pigment component,
• a content of the pigment component contained in the infrared-light-transmitting dark color layer is 20 parts by mass to 50 parts by mass with respect to 100 parts by mass of the main agent resin,
• the pigment component contains a brown pigment and a dark color pigment composed of a phthalocyanine pigment,
• the brown pigment is at least one or more pigments selected from the group consisting of a benzimidazolone pigment, 4-[(2,5-dichlorophenyl)azo]-3-hydroxy-N-(2,5-dimethoxyphenyl)-2-naphthalenecarboxamide, 1-[(4-nitrophenyl)azo]-2-naphthalenol, bis[3-hydroxy-4-(phenylazo)-2-naphthalenecarboxylic acid]copper salt, C. I. Pigment Brown 7, N,N′-bis(2,4-dinitrophenyl)-3,3′-dimethoxy-1,1′-biphenyl-4,4′-diamine, 3,4,9,10-perylenetetracarboxylic diimide, Δ2,2′(1H,1′H)-binaphtho [2,1-b]thiophen-1,1′-dione, and N,N′-(10,15,16,17-tetrahydro-5,10,15,17-tetraoxo)-5H-dinaphtho [2,3-a:
• 2′,3′-i]carbazole-4,9-diyl)bi s(benzamide), and
• an NCO/OH ratio that is a ratio of an NCO value of the curing agent to an OH value of the main agent resin is 1.0 to 2.0.