Patent ID: 7781355

Claim:
A glass strand having a composition comprising the following constituents in the limits defined below, expressed as percentages by weight: SiO 2 58 to 63 Al 2 O 3 10 to 16 CaO 16 to less than 23 MgO 0.5 to less than 3.5 Na 2 O + K 2 O + Li 2 O 0 to 2 TiO 2 greater than 1 but less than 1.5 B 2 O 3 0 to 1.5 Li 2 O 0 to 0.4 ZnO 0 to 0.4 MnO 0 to 1 F 0 to 0.5 and between 10 and 100 ppm of cobalt oxide (CoO).