Infrared reflecting substrate and method for producing same

摘要

This infrared reflecting substrate (100) sequentially comprises, on a transparent base (10), a first metal oxide layer (21), a second metal oxide layer (22) and a metal layer (30) in this order. The second metal oxide layer (22) and the metal layer (30) are in direct contact with each other. The first metal oxide layer (21) has a refractive index of 2.2 or more. It is preferable that the second metal oxide layer (22) is formed of a metal oxide that contains tin oxide and zinc oxide, while having an oxygen content smaller than that of the stoichiometric composition. The second metal oxide layer is preferably formed by a direct current sputtering method. A target which contains zinc atoms and tin atoms and is obtained by sintering a metal powder and zinc oxide and/or tin oxide is preferably used for the formation of the second metal oxide layer. It is preferable that the oxygen concentration in a gas to be introduced into a sputtering film formation chamber is 8% by volume or less. The present invention enables the achievement of an infrared reflecting substrate having high visible light transmittance and excellent durability.