To be fair it does say "reflects solar infrared rays," which I would interpret as "the IR from the Sun" (aka NIR).

The product datasheet[0] claims a thermal emittance (aka LWIR) of 0.82. Having such a high value is typical for non-metallic surfaces.[1]

[0] https://5.imimg.com/data5/CA/RO/MY-653008/excel-cool-coat.pd...

[1] https://ntrs.nasa.gov/api/citations/19840015630/downloads/19...