In the formulation of waterborne industrial coatings, wood finishes, and high-end architectural paints, in-can viscosity development, anti-sagging, flow and leveling, and zero/low-VOC environmental compliance are critical benchmarks of coating quality.

Traditional solvent-borne or small-molecule polyurethane thickeners often drive up VOC content, degrade pot life in two-component waterborne systems (2K WPU), or cause in-can viscosity instability in formulations rich in co-solvents.

Tianjin Ruikel Chemical Co., Ltd. introduces RT-3628SF, a brand-new, solvent-free, non-ionic associative polyurethane (HEUR) thickener. Designed as a direct drop-in replacement for Borchi® Gel L 75 N, RT-3628SF delivers moderate-shear pseudoplastic rheology, can be diluted directly with water in a 1:1 ratio, and provides efficient, stable in-can viscosity buildup alongside exceptional film appearance.

1. Core Technical Features & Physical Parameters

RT-3628SF is a solvent-free, organotin-free, and APEO-free non-ionic associative polyurethane thickener. It combines high thickening efficiency with broad compatibility across various resins and co-solvents.

[Recommended Dosage] ──► 0.3% – 2.0% of total formulation weight (1:1 water pre-dilution recommended in the letdown stage) 

│▼[Rheological Synergy]  ──► Combine with high-shear thickener RT-3629 (Add RT-3629 first, followed by RT-3628SF) 

│▼[High-Shear ICI & Low-Shear KU Balance] ──► Achieve optimal balance between high ICI viscosity (brush drag / film build) and KU viscosity (in-can anti-settling)

Technical Parameters Table

2. Key Performance Advantages

1. Efficient In-Can Viscosity Build & Stability  ：RT-3628SF rapidly establishes system viscosity, delivering superior in-can viscosity and pseudoplasticity that significantly improve anti-settling and anti-sagging performance during storage.

2. Organotin-Free: Zero Impact on Pot Life ：Because it contains no organotin catalysts, RT-3628SF does not catalyze side reactions between -NCO groups and water when used in hydroxypropyl dispersions or 2K waterborne polyurethane systems, ensuring absolute pot-life stability.

3. High Co-Solvent Tolerance for Industrial Paints ：In water-based industrial coatings rich in co-solvents (such as water-based epoxy primers, hydroxypropyl dispersions, and water-based alkyd resins), RT-3628SF delivers robust thickening performance without viscosity drop.

4. Convenient 1:1 Water Dilutability & Easy Handling ：With a moderate supplied viscosity of 6,000 - 12,000\mPa.s, the product can be diluted directly with water in a 1:1 ratio before addition, making it exceptionally easy to incorporate into aqueous phases.

5. Superior Film Appearance & Comprehensive ResistanceProvides exceptional flow, leveling, film fullness, and gloss retention. It also offers superb water resistance, alkali resistance, scrub resistance, stain resistance, and corrosion resistance.

3. Application Fields & Formulation Tips

A. Primary Application Fields

• Water-Based Industrial Coatings: Water-based epoxy primers, polyurethane topcoats, alkyd resins, and high-performance acrylic industrial finishes.

• Wood & Automotive Coatings: Premium water-based clear wood finishes and automotive refinish systems requiring high transparency and flawless leveling.

• Zero/Low-VOC Architectural Paints: High-end interior/exterior latex paints, gloss, and semi-gloss formulations.

B. Usage & Rheological Synergy

[Recommended Dosage] ──► 0.3% – 2.0% of total formulation weight (1:1 water pre-dilution recommended in the letdown stage) 

│▼[Rheological Synergy]  ──► Combine with high-shear thickener RT-3629 (Add RT-3629 first, followed by RT-3628SF) 

│▼[High-Shear ICI & Low-Shear KU Balance] ──► Achieve optimal balance between high ICI viscosity (brush drag / film build) and KU viscosity (in-can anti-settling)

• Recommended Dosage: 0.3% - 2.0% of total formulation weight. It can be added directly or pre-diluted 1:1 with water.

• Synergy with High-Shear Thickeners (RT-3629):To balance high-shear viscosity (ICI viscosity for brush drag and film build) with medium-shear structure, combine RT-3628SF (medium-shear pseudoplastic) with RT-3629 (high-shear leveling thickener). When using them together, add RT-3629 first, followed by RT-3628SF.

• Emulsion Compatibility: Best thickening response and film clarity are achieved when paired with fine-particle, oil-compatible emulsions.

4. Summary & Sample Requests

Ruike Chemical's RT-3628SF provides formulators with an eco-friendly, high-efficiency, solvent-free HEUR thickener that serves as a direct drop-in replacement for Borchi® Gel L 75 N. Optimize your high-performance, low-VOC water-based systems with confidence.

To download Technical Data Sheets (TDS), Safety Data Sheets (SDS), or request free laboratory evaluation samples, visit our technical portal at www.rk-chem.com.

• Visit www.rk-chem.com to explore selection guides for RT-3628SF and our full line of polyurethane thickeners.

• Contact our technical application team today for tailored formulation advice and to request a free laboratory test sample!