Segmentation by type isolates the chemical architecture of sulfurized calcium alkylphenate into two core families, each further divided into functional sub‑categories. The first family, mono‑alkylphenate derivatives, includes mono‑sulfurized and mono‑alkylated grades; these possess a single phenolic ring linked to calcium, delivering targeted dispersancy with lower viscosity impact, and they dominate niche applications such as high‑speed machining where fluid flow is critical. The second family, poly‑alkylphenate derivatives, comprises poly‑sulfurized and poly‑alkylated variants that feature multiple phenolic units, offering superior load‑carrying capacity and enhanced corrosion protection; these are preferred in heavy‑duty metalworking fluids and rubber compounding where robust performance under stress is required. By delineating the functional trade‑offs between mono‑ and poly‑structures, this taxonomy clarifies how each type contributes to the overall market, with poly‑derivatives typically capturing a larger revenue share due to their broader applicability across high‑performance sectors.