about 390 grams was added to the mixture slowly in small increments with mixing carried out between each addition after all of the fina crystal 500 u00ae was added the resulting mixture was thoroughly mixed for about 5 minutes and the material was then transferred to a 2 roll mill the material was milled into sheets having a thickness of about 20 mm and cut into pieces to be used later in this step a moriyama mixer equipped with a ram was also used with the temperature of the mixer being set at 250 u00b0 f the premix made in part 1 of this example was added to the mixer mixing was commenced and 10 grams of carbon black pigment was added to the mixer when the mixture became homogeneous mixing was stopped 60 grams of hisil 233 u00ae hydrated amorphous silica was added to the mixture and mixing was resumed mixing continued until the mixture was homogeneous at which time mixing was again stopped and 140 grams of scotchlite s60 10 000 u00ae glass microspheres was added to the mixture mixing was resumed and was continued until the resulting mixture was homogeneous the temperature of the mixer was set below 160 u00b0 f when the mixer.