Here are a few references for papers on this subject: Infrared reflectance of anodized aluminum as a cryogenic material - J. Yamamoto - Cryogenics, February 1979 (no web reference)
Infrared absorption of optical blacks - http://adsabs.harvard.edu/abs/1979OptEn..18..147S
Infrared reflection properties of five types of black coating for radiometric detectors - http://www.iop.org/EJ/abstract/0022-3735/18/8/010
Review of black surfaces for space-borne infrared systems - http://scitation.aip.org/content/aip/journal/rsi/70/5/10.1063/1.1149739