Technical Specifications
| Property | Value | Test Method |
|---|---|---|
| Chemical name | Isopropyl Tri(N-aminoethyl-aminoethyl) Titanate | — |
| CAS No. | 36673-16-2 | — |
| Active content | ≥95% | GC |
| Appearance | Amber to dark brown liquid | Visual |
| Specific gravity (25°C) | 0.99–1.02 g/cm³ | ASTM D792 |
| Viscosity (25°C) | 20–60 mPa·s | Brookfield LV |
| Flash point | >60°C | ASTM D93 (PMCC) |
| Recommended loading on filler | 0.5–1.5 wt% | — |
| Maximum process temperature | 180°C continuous | — |
| Solubility | Miscible with IPA, toluene, xylene | — |
| Compatible filler BET range | 5–25 m²/g (scale for higher BET) | ISO 9277 |
Industrial Application Scenarios
Self-Bridging Chemistry: How Dual Amino Groups Work
KR-44 is isopropyl tri(N-aminoethyl-aminoethyl) titanate, a monoalkoxy chelate titanate carrying three diaminoethyl ligands. The titanium center bonds to filler surfaces — calcium carbonate, talc, kaolin, silica — via hydrolysis of the isopropyloxy group at the point of contact. The pendant ethylenediamine-ethylamine arms then react with carboxyl, epoxy, or amide functionality in the polymer matrix, forming covalent or strong hydrogen-bonded links. This dual-reactivity — filler surface bond plus resin bond — is what the term ‘self-bridging’ describes. No primer step is required. Effective treatment begins at 0.5 wt% on filler, making KR-44 more cost-efficient per bond formed than monoamino grades. For hydrolytic stability in wet environments, compare KR-238S neoalkoxy chemistry.
Performance in Unsaturated Polyester and FRP Systems
In calcium carbonate–filled UPR at 50–65 phr filler loading, KR-44 at 0.8–1.2 wt% on filler delivers 15–20% tensile strength increase and 25–35% Brookfield viscosity reduction versus untreated compound. The amino groups react with residual carboxyl functionality in styrene-crosslinked polyester networks, strengthening the interfacial shear zone. In sheet molding compound (SMC) and bulk molding compound (BMC), KR-44 reduces mixing energy and improves glass fiber wetting without measurably shifting MEKP-initiated gel time at recommended loadings. Exceeding 1.5 wt% on filler produces diminishing returns: excess titanate migrates to the compound surface, raising VOC from residual isopropanol and softening green-state tack. Bench confirmation at target filler loading is standard practice before scale-up.
Polyamide and Specialty Thermoplastic Applications
In glass-filled PA6 and PA66 compounding (240–270°C processing window), the primary amine groups of KR-44 react directly with polyamide carbonyl bonds, improving fiber-matrix adhesion. Flexural modulus retention after 72-hour conditioning at 50% RH improves 8–12% versus untreated glass fiber, and weld-line tensile strength increases measurably in injection-molded parts where fiber orientation disrupts the matrix. Recommended addition: introduce KR-44 at 0.3–0.8 wt% on glass at the main feeder port. KR-44 also shows activity in PA11 and PA12 systems used in automotive flexible fuel and brake lines, where the amino–titanate interface improves hydrolytic stability under cyclic moisture exposure. For systems requiring superior hydrolytic stability, KR-38S is the monoalkoxy benchmark for comparison.
Supply Chain Position and Procurement Outlook
KR-44 synthesis depends on two upstream feedstocks: titanium tetrachloride (TiCl₄), produced primarily by chlorination of rutile and upgraded ilmenite in Shandong and Yunnan provinces, and ethylenediamine (EDA), a downstream product of ethylene oxide and ammonia subject to energy-price sensitivity. As of Q1 2026, spot TiCl₄ ex-China trades 8–12% above 2024 averages on tight chlorine supply and environmental inspection curtailments; this cost increase flows directly into amino titanate pricing. Long-term quarterly contracts remain 10–15% below spot. Downstream demand is driven by UPR compounders supplying construction and marine FRP, and by PA compounders in automotive. Single-source dependence on China introduces lead-time risk; SEMITECH maintains Taiwan and SEA-region inventory enabling 2–3 week delivery to North America and Europe versus 8–14 weeks for direct China import.
Frequently Asked Questions
Self-Bridging Chemistry: How Dual Amino Groups Work
KR-44 is isopropyl tri(N-aminoethyl-aminoethyl) titanate, a monoalkoxy chelate titanate carrying three diaminoethyl ligands. The titanium center bonds to filler surfaces — calcium carbonate, talc, kaolin, silica — via hydrolysis of the isopropyloxy group at the point of contact. The pendant ethylenediamine-ethylamine arms then react with carboxyl, epoxy, or amide functionality in the polymer matrix, forming covalent or strong hydrogen-bonded links. This dual-reactivity — filler surface bond plus resin bond — is what the term ‘self-bridging’ describes. No primer step is required. Effective treatment begins at 0.5 wt% on filler, making KR-44 more cost-efficient per bond formed than monoamino grades. For hydrolytic stability in wet environments, compare KR-238S neoalkoxy chemistry.
Performance in Unsaturated Polyester and FRP Systems
In calcium carbonate–filled UPR at 50–65 phr filler loading, KR-44 at 0.8–1.2 wt% on filler delivers 15–20% tensile strength increase and 25–35% Brookfield viscosity reduction versus untreated compound. The amino groups react with residual carboxyl functionality in styrene-crosslinked polyester networks, strengthening the interfacial shear zone. In sheet molding compound (SMC) and bulk molding compound (BMC), KR-44 reduces mixing energy and improves glass fiber wetting without measurably shifting MEKP-initiated gel time at recommended loadings. Exceeding 1.5 wt% on filler produces diminishing returns: excess titanate migrates to the compound surface, raising VOC from residual isopropanol and softening green-state tack. Bench confirmation at target filler loading is standard practice before scale-up.
Polyamide and Specialty Thermoplastic Applications
In glass-filled PA6 and PA66 compounding (240–270°C processing window), the primary amine groups of KR-44 react directly with polyamide carbonyl bonds, improving fiber-matrix adhesion. Flexural modulus retention after 72-hour conditioning at 50% RH improves 8–12% versus untreated glass fiber, and weld-line tensile strength increases measurably in injection-molded parts where fiber orientation disrupts the matrix. Recommended addition: introduce KR-44 at 0.3–0.8 wt% on glass at the main feeder port. KR-44 also shows activity in PA11 and PA12 systems used in automotive flexible fuel and brake lines, where the amino–titanate interface improves hydrolytic stability under cyclic moisture exposure. For systems requiring superior hydrolytic stability, KR-38S is the monoalkoxy benchmark for comparison.
Supply Chain Position and Procurement Outlook
KR-44 synthesis depends on two upstream feedstocks: titanium tetrachloride (TiCl₄), produced primarily by chlorination of rutile and upgraded ilmenite in Shandong and Yunnan provinces, and ethylenediamine (EDA), a downstream product of ethylene oxide and ammonia subject to energy-price sensitivity. As of Q1 2026, spot TiCl₄ ex-China trades 8–12% above 2024 averages on tight chlorine supply and environmental inspection curtailments; this cost increase flows directly into amino titanate pricing. Long-term quarterly contracts remain 10–15% below spot. Downstream demand is driven by UPR compounders supplying construction and marine FRP, and by PA compounders in automotive. Single-source dependence on China introduces lead-time risk; SEMITECH maintains Taiwan and SEA-region inventory enabling 2–3 week delivery to North America and Europe versus 8–14 weeks for direct China import.
+Q: What is the difference between KR-44 and KR-38S for UPR applications?
A: KR-38S is a monoalkoxy titanate without amino functionality; it promotes adhesion primarily via esterification with hydroxyl groups on the filler surface. KR-44 adds dual amino arms that react with carboxyl and epoxy groups in UPR, producing a stronger interfacial bridge. For unfilled or lightly filled UPR (50 phr CaCO₃), KR-44’s self-bridging mechanism delivers measurable tensile and viscosity advantages that KR-38S cannot match.
+Q: Can KR-44 be used in waterborne or aqueous resin systems?
A: KR-44 is not suitable for fully aqueous systems. The isopropyloxy group hydrolyzes rapidly above pH 7, generating isopropanol and precipitating titanium oxide species. For water-based coatings or latex formulations, neoalkoxy grades such as KR-238S with controlled hydrolysis kinetics are preferred. KR-44 performs best when pre-dispersed in a compatible solvent — isopropanol, xylene, or toluene — before addition to dry filler, or when treating filler in a high-intensity dry mixer prior to resin blending.
+Q: Which fillers respond best to KR-44 surface treatment?
A: KR-44 works best on fillers with abundant surface hydroxyl groups: precipitated and ground calcium carbonate, kaolin, talc, wollastonite, and glass fiber. Silica (fumed and precipitated) also responds well. Carbon black and organic fillers show limited response. Optimal BET surface area for consistent treatment is 5–25 m²/g; for fumed silica or high-surface precipitated silica above 100 m²/g, loading must be scaled proportionally to available surface area, or treatment efficiency drops significantly.
+Q: How does KR-44 unit cost compare to amino silane coupling agents for UPR?
A: KR-44 typically prices 20–40% above equivalent amino silane grades (e.g., A-1100) on a per-kilogram basis. However, effective loading on filler is often 30–50% lower by weight than silane, making total treatment cost comparable. The cost calculus shifts further in KR-44’s favor in high-CaCO₃ systems: amino silanes show limited adhesion promotion on carbonate surfaces because they require surface silanols, while amino titanates bond effectively to carbonate hydroxyls — making KR-44 the cost-efficient choice for the most common UPR filler package.
+Q: What supply chain risks should procurement teams account for with KR-44?
A: KR-44 supply concentrates in China, where TiCl₄ and ethylenediamine feedstocks are exposed to environmental inspection shutdowns and energy rationing cycles. Spot amino titanate pricing is 8–12% above 2024 levels as of Q1 2026. Procurement teams should target 6–8 weeks of safety stock, qualify at least two approved sources, and consider quarterly pricing contracts, which have held 10–15% below spot. Suppliers with Taiwan or SEA-region inventory reduce import lead time from 8–14 weeks (direct China) to 2–3 weeks.
+Q: Is KR-44 compatible with MEKP peroxide cure systems in UPR?
A: KR-44 is compatible with standard peroxide initiators — MEKP, cumene hydroperoxide, and BPO — at recommended loadings of 0.5–1.5 wt% on filler. The amino groups do not consume meaningful peroxide quantities in this range. At loadings above 2 wt%, slight gel time extension has been observed in some calcium carbonate–filled systems, attributed to the basic character of the diamine groups locally buffering the acid co-promoter. Bench confirmation with the specific resin grade and initiator system is recommended before committing to production scale.
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