Patent ID: 7105047

Claim:
A thermal protective coating, comprising: in dry admixture, a. from about 5% to about 30% of an alkali/alkaline earth metal silicate taken from the group consisting of sodium silicate, potassium silicate, calcium silicate, and magnesium silicate; b. from about 45% to about 92% of a filler taken from the group consisting of silicon dioxide, aluminum oxide, titanium dioxide, magnesium oxide, calcium oxide, and boron oxide; and c. from about 2% to about 20% of one or more emissivity agents taken from the group consisting of silicon hexaboride, boron carbide, silicon tetraboride, silicon carbide powder, molybdenum disilicide, tungsten disilicide, zirconium diboride, cupric chromite, and metallic oxides; d. wherein the coating is essentially phosphate free.