Chemical Index TA1 TA2 A1 A0 Fine1 Fine2 Name Unit Content Moisture %≦ 1 1 1 1 1 1 Ash Content %≦ 10 10 10 12 12 15 Acetone Extract %≦ 18 18 22 20 25 28 Physical Index Specific Gravity g/cm3≦ 1.18 1.18 1.24 1.20 1.26 1.35 Tensile Strength Mpa≧ 15 12 10 12 8 6.5 Elongation At Break %≧ 420 400 380 400 350 300 Mooney Viscosity 1+4≦ 90 90 80 80 85 85