Black gum rosin is mainly used for tire reclaimed rubber production and industrial rubber products production. It is an ideal replacement for yellow gum rosin to reduce production cost but reclaim rubber quality is the same. Items Specification Appearance Dark brown Softening Point (R&B) 73 Acidity (KOH mg/g) 130.0 max Unsaponifiable Matter, % 6.0 max Ethanol Insolubles, % 0.06 max Ash Content, % 0.05 max Features: As  a kind of thickening agent, for increasing elongation percentage, it is mainly used for reclaimed rubber and high-end rubber products. Besides black gum rosin, other rubber chemicals also can be sent to you, like rubber reclaiming agent, special-made pine tar oil, environment-friendly oil, reinforcing agent, etc. Any inquiry, pls contact sofia.chu(at)zzdenglan.com freely.