SEMITECH KR-46B — Treated Isopropyl Tri(dioctyl phosphato) Titanate
KR-46B sits at the intersection of two upstream chains: isopropyl titanate (IPT) and 2-ethylhexanol-derived dioctyl phosphate. IPT is produced in volume by a handful of Chinese and Japanese manufacturers (Teijin, Dorf Ketal, and domestic Chinese producers account for ~80% of global supply); spot prices tracked in Q1 2026 ranged from $4.20–$5.10/kg CFR China, up 22% year-on-year driven by tighter TiCl₄ feedstock from rutile ore constraints in Yunnan province. Dioctyl phosphate (DOP-acid) is a plasticizer-chain derivative; supply tightened in H2 2025 as 2-ethylhexanol capacity in Southeast Asia shifted to n-butanol demand from EV battery solvent applications. Combined, these upstream pressures add $0.35–0.55/kg to KR-46B production cost versus the 2024 baseline. Buyers on annual contracts established in Q3 2025 remain insulated; spot buyers should evaluate KR-9S (neopentyl phosphato titanate) as a cost-hedge alternate for less critical substrates.
Technical Specifications
| Raw Material | Key Producers | Supply Status (Q1 2026) | Price Trend |
|---|---|---|---|
| Isopropyl titanate (IPT) | Teijin (JP), Dorf Ketal (IN), Shaanxi Sino (CN) | Tight; rutile/TiCl₄ constraints | ↑ +22% YoY |
| Dioctyl phosphoric acid | BASF, LG Chem, Aekyung (KR) | Moderate tightness; EV solvent demand displacing capacity | ↑ +8% YoY |
| 2-Ethylhexanol (upstream) | Sasol, INEOS, Shandong Yuhuang (CN) | Recovering; new CN capacity online Q2 2026 | → Stable to slight relief |
| Isopropanol (IPA) | Regional commodity; abundant | Ample supply | ↓ Slight softening |
Supply Chain Position and Raw Material Risk
KR-46B sits at the intersection of two upstream chains: isopropyl titanate (IPT) and 2-ethylhexanol-derived dioctyl phosphate. IPT is produced in volume by a handful of Chinese and Japanese manufacturers (Teijin, Dorf Ketal, and domestic Chinese producers account for ~80% of global supply); spot prices tracked in Q1 2026 ranged from $4.20–$5.10/kg CFR China, up 22% year-on-year driven by tighter TiCl₄ feedstock from rutile ore constraints in Yunnan province. Dioctyl phosphate (DOP-acid) is a plasticizer-chain derivative; supply tightened in H2 2025 as 2-ethylhexanol capacity in Southeast Asia shifted to n-butanol demand from EV battery solvent applications. Combined, these upstream pressures add $0.35–0.55/kg to KR-46B production cost versus the 2024 baseline. Buyers on annual contracts established in Q3 2025 remain insulated; spot buyers should evaluate KR-9S (neopentyl phosphato titanate) as a cost-hedge alternate for less critical substrates.
| Raw Material | Key Producers | Supply Status (Q1 2026) | Price Trend |
|---|---|---|---|
| Isopropyl titanate (IPT) | Teijin (JP), Dorf Ketal (IN), Shaanxi Sino (CN) | Tight; rutile/TiCl₄ constraints | ↑ +22% YoY |
| Dioctyl phosphoric acid | BASF, LG Chem, Aekyung (KR) | Moderate tightness; EV solvent demand displacing capacity | ↑ +8% YoY |
| 2-Ethylhexanol (upstream) | Sasol, INEOS, Shandong Yuhuang (CN) | Recovering; new CN capacity online Q2 2026 | → Stable to slight relief |
| Isopropanol (IPA) | Regional commodity; abundant | Ample supply | ↓ Slight softening |
Industrial Application Scenarios
Chemical Identity and Surface Chemistry Rationale
KR-46B is isopropyl tri(dioctyl phosphato) titanate, a monoalkoxy titanate where three dioctyl phosphate ligands are coordinated to the titanium center. The phosphate groups chemisorb onto hydroxyl-rich surfaces of inorganic pigments—TiO₂, CaCO₃, BaSO₄, and kaolin—via proton exchange, forming a covalent Ti–O–P bond at the particle surface. This reaction displaces physisorbed water monolayers that otherwise aggregate particles and increase viscosity. The two octyl chains on each phosphate arm extend into the organic binder phase, providing steric stabilization and improving pigment–resin wettability. Unlike pyrophosphato variants, the mono-phosphate structure in KR-46B gives a denser surface monolayer on high-BET substrates (>10 m²/g), making it the preferred B-grade specification for pigment-heavy industrial formulations.
Dosing Efficiency Versus KR-12
KR-12 (isopropyl tri(dioctyl pyrophosphato) titanate) is the reference phosphate titanate in many coatings formularies, but its pyrophosphate ligands occupy more surface area per molecule, requiring higher mass loading to achieve full monolayer coverage on fine pigments. KR-46B reaches equivalent dispersion quality—measured by Hegman fineness, gloss at 60°, and post-grind viscosity stability—at 0.5–0.8 wt% on pigment weight versus 0.7–1.1 wt% for KR-12 under identical processing conditions. In a 40% PVC TiO₂ alkyd system, internal trials show KR-46B reduces grind time by 12–18% and lowers post-let-down viscosity by 8–15 KU. For formulators sourcing on spot markets where KR-12 carries a price premium, KR-46B represents a structurally justified, cost-rational substitution—not a downgrade.Recommended loading — 0.5–0.8 wt% on total inorganic pigment weight; optimize by grind fineness (Hegman 6–7 target)Compatibility — Solvent-borne alkyds, epoxies, polyurethanes; partial compatibility with waterborne systems when pre-diluted in co-solventMixing order — Add to mill-base before pigment charge; pre-dilute 1:1 in mineral spirits for easier dispersion
Application Parameters and Thermal Stability
KR-46B is a pale-yellow liquid at room temperature with viscosity of 15–30 cP at 25°C and a flash point of approximately 93°C (closed cup), making it compatible with standard industrial mixing equipment without special handling. Thermal stability extends to 200°C, covering all solvent-borne stoving enamel cure cycles (120–180°C) without titanate decomposition or yellowing. BET surface area of the treated pigment substrate should fall in the 5–50 m²/g range for best results; for ultra-fine TiO₂ grades with BET >80 m²/g (e.g., Kronos 2310), increase loading by 15% and verify by grind plate test. Do not combine with strong acids (pH
Frequently Asked Questions
Chemical Identity and Surface Chemistry Rationale
KR-46B is isopropyl tri(dioctyl phosphato) titanate, a monoalkoxy titanate where three dioctyl phosphate ligands are coordinated to the titanium center. The phosphate groups chemisorb onto hydroxyl-rich surfaces of inorganic pigments—TiO₂, CaCO₃, BaSO₄, and kaolin—via proton exchange, forming a covalent Ti–O–P bond at the particle surface. This reaction displaces physisorbed water monolayers that otherwise aggregate particles and increase viscosity. The two octyl chains on each phosphate arm extend into the organic binder phase, providing steric stabilization and improving pigment–resin wettability. Unlike pyrophosphato variants, the mono-phosphate structure in KR-46B gives a denser surface monolayer on high-BET substrates (>10 m²/g), making it the preferred B-grade specification for pigment-heavy industrial formulations.
Dosing Efficiency Versus KR-12
KR-12 (isopropyl tri(dioctyl pyrophosphato) titanate) is the reference phosphate titanate in many coatings formularies, but its pyrophosphate ligands occupy more surface area per molecule, requiring higher mass loading to achieve full monolayer coverage on fine pigments. KR-46B reaches equivalent dispersion quality—measured by Hegman fineness, gloss at 60°, and post-grind viscosity stability—at 0.5–0.8 wt% on pigment weight versus 0.7–1.1 wt% for KR-12 under identical processing conditions. In a 40% PVC TiO₂ alkyd system, internal trials show KR-46B reduces grind time by 12–18% and lowers post-let-down viscosity by 8–15 KU. For formulators sourcing on spot markets where KR-12 carries a price premium, KR-46B represents a structurally justified, cost-rational substitution—not a downgrade.Recommended loading — 0.5–0.8 wt% on total inorganic pigment weight; optimize by grind fineness (Hegman 6–7 target)Compatibility — Solvent-borne alkyds, epoxies, polyurethanes; partial compatibility with waterborne systems when pre-diluted in co-solventMixing order — Add to mill-base before pigment charge; pre-dilute 1:1 in mineral spirits for easier dispersion
Application Parameters and Thermal Stability
KR-46B is a pale-yellow liquid at room temperature with viscosity of 15–30 cP at 25°C and a flash point of approximately 93°C (closed cup), making it compatible with standard industrial mixing equipment without special handling. Thermal stability extends to 200°C, covering all solvent-borne stoving enamel cure cycles (120–180°C) without titanate decomposition or yellowing. BET surface area of the treated pigment substrate should fall in the 5–50 m²/g range for best results; for ultra-fine TiO₂ grades with BET >80 m²/g (e.g., Kronos 2310), increase loading by 15% and verify by grind plate test. Do not combine with strong acids (pH
+Q: What is the difference between KR-46B and KR-12, and when should I choose KR-46B?
A: KR-46B uses a mono-phosphate ligand; KR-12 uses a pyrophosphate ligand. KR-46B achieves full monolayer coverage on medium-BET pigments at 15–25% lower mass loading, reducing additive cost per batch. Choose KR-46B when your pigment BET is 5–50 m²/g and grind efficiency matters; choose KR-12 for very high-surface pigments above 80 m²/g.
+Q: Can KR-46B be used in waterborne coatings systems?
A: KR-46B is primarily designed for solvent-borne systems. It can be incorporated into waterborne formulations if pre-diluted 1:1 in a water-miscible co-solvent (e.g., propylene glycol) before addition to the mill-base, but hydrolytic stability is limited. For dedicated waterborne systems, evaluate KR-9S or a silane-titanate hybrid designed for aqueous pH ranges.
+Q: What inorganic pigments respond best to KR-46B treatment?
A: KR-46B is optimized for hydroxyl-rich oxide and sulfate surfaces: rutile TiO₂ (BET 5–25 m²/g), precipitated CaCO₃ (BET 5–20 m²/g), BaSO₄, and calcined kaolin. It is less effective on carbon black (low hydroxyl density) and organic pigments; for those substrates, evaluate titanate-kr-9s with its alkyl sulfonate ligand.
+Q: How do I determine the optimal loading level for my specific pigment?
A: Start with 0.65 wt% on pigment weight as a baseline. Grind a series at 0.4, 0.6, 0.8, and 1.0 wt%, then measure post-grind Hegman fineness and 24-hour viscosity stability. The optimal loading is the lowest level that achieves Hegman 6.5+ with
+Q: Is KR-46B compatible with amine-cured epoxy systems?
A: Yes, with precautions. KR-46B is stable in the uncured epoxy resin phase. Add it to the resin component, not the hardener. Strong aliphatic amines at high concentration can compete with pigment surface sites; if using >20 phr polyamine hardener, verify by contact angle measurement that surface treatment is retained post-cure.
+Q: What is the current price range for KR-46B and are there supply constraints?
A: KR-46B pricing in Q1 2026 ranges from $12–17/kg depending on order volume and origin, reflecting upstream isopropyl titanate tightness (+22% YoY) and dioctyl phosphate cost increases. Buyers on spot terms should consider locking quarterly contracts or evaluating KR-9S as a hedge. Supply from Chinese producers remains available but lead times extended from 2 to 4–5 weeks.
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