Abstract: Carbon blacks having an I.sub.2 No. of 65-112 mg/g, preferably 73-104 mg/g, more preferably 75-99 mg/g, and a primary particle size of not greater than 20 nm particularly well suited for use in the production of polymer compositions. Also described are polymer compositions incorporating the new carbon blacks.

Abstract: New classes of carbon blacks which may be broadly characterized as having an Iodine adsorption number (I.sub.2 No.) of 50-112 milligrams/gram (mg/g) and a primary particle size measured in accordance with the procedures in ASTM Test Procedure D3849-89 (hereinafter denoted as "primary particle size") of less than or equal to 25 nanometers (nm). Certain of the carbon blacks of the present invention may be further characterized as having a CDBP (dibutyl absorption value of the crushed carbon black) of less than or equal to 102 cubic centimeters DBP per 100 grams of carbon black (cc/100 g). The present invention provides carbon blacks having I.sub.2 No. of 65-95 mg/g and a primary particle size of less than or equal to 20 nm. Also disclosed and claimed are carbon blacks having an I.sub.2 No. of 100-112 mg/g and a primary particle size of less than or equal to 20 nm. The present invention further provides carbon blacks having an I.sub.2 No.