Patent ID: 8449670

Claim:
An inorganic binder having calcium silicate sites which are connected the one with the other by alumina-silica phosphate bonds, whereby at least a portion of the alumina-silica phosphate bonds are alumina-boron-silica phosphate bonds, the calcium silicate sites acting as cross-linking sites for the alumina-silica phosphate bonds, whereby the alumina-silicate phosphate bonds have: a weight ratio Al 2 O 3 /SiO 2 ranging from 0.3:1 to 10:1, a weight ratio Al 2 O 3 /P 2 O 5 ranging from 0.0005 to 0.04, and a weight ratio P/B ranging from 20:1 to 100:1, and whereby the inorganic binder further comprises a silicon containing compound selected from the group consisting of waterproof silicon compounds, water repellent silicon compounds and mixtures thereof, the weight ratio of the silicon containing compound/P+B being comprised between 1:5000 and 1:10, and whereby at least a portion of the calcium silicate sites are at least partially coated with a layer of the silicon containing compound.