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High performance transparent blue tone White pigment paste is hard to grind for special particle structure. Today we would like to share a standard preparation method to produce transparent blue tone White pigment paste with Kmeris micro nano titanium dioxide micro Titanium Dioxide RM-530L, which Is alternative to UV-TITAN L 530. Based on the key principle that nano-materials require thorough wetting and grinding to break down agglomerates and achieve optimal dispersion. The below formulation and process outlined below are suitable for most automotive refinish coatings and general industrial solvent-borne applications. The following formulation is recommended for general solvent-borne systems, particularly suitable for automotive refinish paints:     Component Function Weight Percentage Solvent (Butyl Acetate) Solvent / Diluent 13.5% Kmeris Nano-Titanium Dioxide Pigment 30.0% Dispersant KBS-F500/50 Wetting & Dispersing Agent 5.0% Acrylic Resin Binder / Film-Former 51.5% Total   100.0%   Remark:   BYK-180 can be used as a substitute for KBS-F500/50. When substituting, the dosage of BYK-180 should be adjusted based on its performance characteristics. Corresponding adjustments should be made to the solvent content to maintain the total formulation balance. Below are the Equipment and Materials for your reference.       Item Specification / Requirement Bead mill / Sand mill Horizontal or vertical sand mill Grinding media Zirconia beads, diameter 1.0 – 1.5 mm Bead filling ratio 70% – 80% of mill chamber volume Mixing vessel Suitable container for pre-mixing High-speed disperser For pre-dispersion prior to milling After preparing the raw material and equipment, next is the Preparation Procedure. Step 1: Pre-Mixing Weigh all formulation components according to the percentages listed above. Charge the solvent (butyl acetate) into a clean mixing vessel. Add the dispersant (KBS-F500/50 or BYK-180) and acrylic resin to the solvent, and mix thoroughly until homogeneous. Gradually add the Kmeris nano-titanium dioxide powder to the liquid mixture while stirring continuously. Continue stirring at moderate speed until all pigment particles are wetted and a uniform paste is formed. If available, use a high-speed disperser at 1,500–2,500 rpm for 10–15 minutes to achieve initial dispersion and break down large agglomerates. Step 2: Bead Milling (Grinding) Transfer the pre-mixed paste into the sand mill hopper or feed tank. Ensure the mill chamber is filled with zirconia beads (1.0–1.5 mm diameter) at a 70%–80% filling ratio. Start the mill and circulate the paste through the grinding chamber. Operate the mill in recirculation mode — continuously circulating the paste until the required fineness is achieved. Step 3: Fineness Inspection Periodically take samples from the circulating paste. Measure the particle fineness using a Heitman gauge / grindometer (fineness of grind gauge). Continue milling until the desired fineness specification is reached (typically ≤ 5–10 μm for nano-TiO₂ pigment pastes, or as per the specific end-use requirement). Step 4: Discharge and Filtration Once the target fineness is achieved, discharge the finished pigment paste from the mill. If necessary, filter the paste through a screen or filter bag to remove any oversize particles or worn beads. Process Parameters Summary     Parameter Recommended Value Pre-mixing speed 1,500 – 2,500 rpm Pre-mixing time 10 – 15 minutes Bead size 1.0 – 1.5 mm (zirconia) Bead fill ratio 70% – 80% Milling mode Recirculation (loop milling) Milling temperature Monitor and control below 45–50°C to avoid resin degradation Target fineness As specified (typically ≤ 5–10 μm) Quality Control Checks After preparation, the following quality parameters should be verified:     Parameter Test Method Acceptance Criteria Fineness of grind Grindometer (Heitman gauge) As per specification Viscosity Ford cup or rotational viscometer Within target range Solid content Oven drying method Matches formulation Color strength Spectrophotometer vs. standard Acceptable tolerance Storage stability 7-day / 30-day aging test No settling or viscosity drift Notes and Recommendations Wetting is critical: Nano-titanium dioxide has a high surface area and strong tendency to agglomerate. Ensure the dispersant is fully dissolved in the solvent system before adding the pigment. Temperature control: During milling, friction may cause temperature rise. Excessive heat can degrade the resin or alter the dispersion quality. Use a cooling water jacket if available and keep the mill temperature below 45–50°C. Bead filling ratio: Maintaining 70%–80% bead fill is essential for efficient grinding. Lower fill ratios reduce grinding efficiency, while higher ratios may cause excessive heat generation or mill blockage. Dispersant adjustment: When using BYK-180 as a replacement for KBS-F500/50, the optimal dosage may vary. It is recommended to conduct a small-scale trial to determine the optimum dispersant level before full-scale production. Solvent adjustment: Any change in dispersant type or dosage should be compensated by adjusting the solvent content to maintain the total formulation at 100%. Storage: Store the finished pigment paste in sealed containers, away from direct sunlight and heat sources, to prevent solvent evaporation and skin formation.

For automotive coatings, where durability, aesthetics, and application efficiency are paramount, the selection of CAB (Cellulose Acetate Butyrate) pigment chips hinges on several non-negotiable performance parameters. When evaluating these pre-dispersed pigments, leading manufacturers and paint formulators focus on:   1. Pigment Quality & Performance Color Strength & Clarity: The chip must deliver maximum color development with minimal pigment loading, ensuring vibrant, deep, and pure shades—critical for topcoats and solid colors. Weather Fastness & Lightfastness: For exterior automotive parts, pigments must exhibit exceptional resistance to UV radiation and atmospheric conditions to prevent fading, chalking, or color shift over the vehicle's lifespan. Heat Stability: The pigment must withstand the high temperatures encountered during paint curing and drying processes without degrading or altering color.   2. Dispersion Quality & Resin Compatibility Fineness of Grind (Dispersion Level): The degree of pigment dispersion directly impacts gloss, haze, and transparency. Poor dispersion leads to surface defects, reduced gloss, and color inconsistency. CAB Resin Compatibility: The chosen CAB resin grade (e.g., CAB-381-0.5, CAB-551-0.2) dictates the chip's solubility, viscosity, and compatibility with other coating resins (like acrylics, polyesters) used in the final paint formulation.   3. Application & Handling Properties Ease of Incorporation: The chip should dissolve readily in standard solvents, requiring low shear and minimal milling time, which streamlines the paint production process and saves energy. Batch-to-Batch Consistency: Tight control over pigment concentration, dispersion quality, and physical form (size, dust-free nature) is essential for reproducible color matches in production.   4. Regulatory & Sustainability Compliance VOC Content: Low-solvent or solvent-free solid chips help formulators reduce the overall VOC (Volatile Organic Compound) footprint of their paints. Certifications: Adherence to international standards like ISO 9001 (Quality), ISO 14001 (Environment), and OHSAS 18001 (Safety) assures a reliable and responsible supply chain. In the demanding world of automotive OEM, refinish, and interior/exterior decorative paints, perfection is not an option—it's a requirement. Every layer, every hue, and every finish must perform flawlessly against the rigors of time, weather, and use. That is why leading paint manufacturers across Europe, North America, the Middle East, and Asia trust Klarint Material Technology, a premier manufacturer of pre-dispersed pigment solutions under the China AAB group, to deliver that edge.   Our Transparent Nano CAB Pigment Chips are engineered to meet—and exceed—the most stringent parameters of the automotive industry. We don't just supply pigments; we provide a foundation of excellence for your coatings. Welcome to contact us for more discussion to working together to advance the High performance coloring Solutions industry.

In the automotive coatings industry, every link—from the mirror-like gloss of a new car on the production line, to the fast turnaround of repair paints, and the precise delivery of personalized colors—places stringent demands on additive performance. As a high-performance synthetic aldehyde resin, Kabasph® Aldehyde Resin SH-98S, with its high gloss, high hardness, and excellent yellowing resistance, is delivering a solution that combines performance and cost-effectiveness across four core application scenarios in automotive coatings. Key Technical Specifications and Positioning Kabasph® Aldehyde Resin SH-98S is a white to light yellow transparent solid granular resin with the following key technical specifications: Parameter Typical Value Test Method Softening Point 90–105°C ISO 4625-1:2004 Gardner Color (50% solution) < 1 ISO 4630-1:2004 Acid Value ≤ 3 mgKOH/g ISO 2114:2004 Hydroxyl Value 50–80 mgKOH/g DIN 53240-2:1998 Density 1.10 ± 0.05 g/cm³ ISO 1183-1:2004(E)B Notably, Kabasph® Aldehyde Resin SH-98S maintains consistency with BASF's Laropal® A 81 in most specifications while offering a broader hydroxyl value range (50–80 vs. approximately 40), providing greater formulation flexibility. In universal colorant applications, material costs can be reduced by over 30% compared to similar imported products—a significant advantage for paint manufacturers pursuing cost-effectiveness.   Scenario 1: Automotive OEM Coatings – The Hardness and Weathering Cornerstone in Baking Systems OEM coatings represent the most important protective layer in a vehicle's lifecycle, enduring high-temperature baking on the production line and long-term exposure to UV radiation and climatic erosion. Kabasph® Aldehyde Resin SH-98S contributes to OEM coatings in three core aspects: Hardness and Scratch Resistance: Participates in the baking crosslinking network to enhance film surface hardness, effectively reducing scratch defects during assembly line handling. Gloss Enhancement: Its high refractive index imparts a deep mirror-like effect to the paint surface, meeting OEMs' stringent appearance standards for new vehicles. Weathering Improvement: Excellent light and thermal stability significantly retard UV-induced yellowing and chalking, ensuring long-lasting color durability even after years of outdoor exposure. For OEM formulators, SH-98S offers stable performance gains within the recommended addition range without requiring major alterations to existing processes.   Scenario 2: Automotive Refinish Paints – A Fast-Drying Solution for Time-Sensitive Quality Repair Recommended Addition Level: 2%–6% Refinish paints directly face the pressing reality of "time is money" in repair workshops. SH-98S precisely addresses three major pain points in this scenario: Reduced Drying Time: Accelerates solvent release and physical drying, particularly effective in low-temperature or high-humidity spot repairs, helping shops improve turnaround efficiency. Gloss and Hardness Matching: Ensures good visual and physical integration between the repaired area and the original OEM paint in terms of gloss and hardness, avoiding a "patched" appearance. Weathering Consistency: Since repair areas often have uneven film thickness and can become weak points for aging, the Aldehyde Resin SH-98S's weathering contribution effectively narrows the lifespan gap between the repaired zone and the surrounding paint. The product is applicable in various refinish systems including nitrocellulose, polyurethane, and amino baking enamels. Its broad compatibility allows performance upgrades without significant reformulation efforts.   Scenario 3: Motorcycle / Bicycle Paints – High Fullness Requirements for Small Surfaces Recommended Addition Level: 2%–6% Although motorcycles and bicycles have smaller coated areas than automobiles, users are equally sensitive to color vibrancy, film fullness, and outdoor weathering performance. Our Aldehyde Resin SH-98S plays a direct role here: Enhanced Fullness: Improves film leveling, giving curved components like frames and fuel tanks a rich, rounded visual effect that significantly elevates product grade. Weathering Assurance: As two-wheelers are often parked outdoors, SH-98S effectively inhibits chalking and gloss loss, maintaining color freshness over years of use.   Scenario 4: Universal Colorants (Grinding Resins) – A Cost-Reducing, Efficiency-Boosting Dispersion Engine Recommended Addition Level (liquid formulation): 30%–60% This is arguably SH-98S's most transformative application. As a grinding resin, it delivers a dual breakthrough: Dispersion Efficiency and Storage Stability: With excellent pigment wetting properties and low solution viscosity, SH-98S effectively reduces milling time, prevents pigment flocculation and re-agglomeration, and ensures consistent color strength and viscosity even after long-term storage. Significant Cost Reduction: While delivering performance comparable to imported alternatives, material costs can be lowered by over 30%—a tangible margin improvement for colorant producers.   Conclusion: Performance and Economic Value Across the Entire Value Chain From OEM coatings on new car production lines, to fast-drying refinish paints at repair terminals, to the delicate finishes on two-wheelers, and even the upfront preparation of colorants—Kabasph® Aldehyde Resin SH-98S provides differentiated solutions for the entire automotive coatings value chain from a single core chemistry platform. Its technical equivalence to Laropal® A 81, combined with significant cost advantages, makes it an ideal choice for automotive coating manufacturers pursuing both quality excellence and cost optimization.

In automotive coating systems, a high-performance film must do more than just look stunning—it must also withstand the harshest environmental challenges, resist chemical attack, ensure flawless application, and deliver uncompromising durability over the long haul. As automotive finishing technologies advance—particularly in premium refinish, interior trim, plastic components, and high-end topcoats—CAB (Cellulose Acetate Butyrate) has earned its place as a value-driving functional resin that formulators increasingly rely on.   What does CAB resin do in automotive paint? CAB functions as a versatile performance enhancer—fine-tuning leveling, boosting gloss, accelerating drying, preventing sagging, and unlocking superior pigment dispersion. The result? Coatings that not only look exceptional but also perform reliably, coat after coat.   Selecting the right CAB grade for your automotive application, however, is anything but one-size-fits-all. It demands a deep understanding of your specific end-use requirements and formulation dynamics—and that's where informed expertise makes all the difference.   The first step in CAB selection isn't poring over technical data sheets—it's pinpointing the pain points in your formulation. In automotive coatings, CAB delivers core value across several key dimensions:   Ⅰ. What's your formulation's biggest headache—and can CAB cure it? Fast drying: CAB significantly shortens the tack-free time of coating films. Data shows that incorporating CAB into acrylic polyol clearcoats can reduce dust-free drying time by approximately 25%. This is especially critical in refinish applications—where body shops lack the high-temperature baking ovens used in OEM lines—because faster drying directly translates to higher throughput and quicker job turnaround.   Metallic pigment orientation: CAB promotes the parallel alignment of aluminum flakes and pearlescent pigments within the film, enhancing the flop effect (color travel) and giving metallic finishes a richer, more premium visual appearance.   Resist lifting: In basecoat systems, CAB acts as a barrier against solvent penetration from the overlying clearcoat, preventing the base layer from being "lifted" or swollen—a common cause of mottled or uneven color appearance.   Improved leveling and defect reduction: Functioning as a leveling aid, CAB minimizes surface imperfections such as cratering and orange peel, while boosting distinctness of image (DOI) for a mirror-like finish.   Weather resistance and anti-yellowing: CAB is inherently UV-stable, ensuring that clearcoats remain water-white and color-true over time—a non-negotiable requirement for automotive exterior finishes.   Ⅱ. How to know the key parameters of CAB?   The CAB grade designation—such as CAB-381-0.5—is itself the very first piece of information you need for selection, as it reveals the resin's three core parameters: 1. Butyryl Content – Dictates hardness and compatibility A higher butyryl content (e.g., the 551 series) delivers greater flexibility and broader compatibility with most coating resins, making it an ideal partner in versatile formulations. A lower butyryl content (e.g., the 171 series), on the other hand, yields higher film hardness and enhanced chemical resistance—perfect for applications where durability takes priority.   2. Hydroxyl Content – Determines reactivity High-hydroxyl grades can crosslink with curing agents to form a denser, more robust polymer network, offering superior film integrity. Low-hydroxyl grades remain more stable and are better suited for non-crosslinking systems, where simplicity and consistency are key.   3. Viscosity – Impacts application solids and leveling Low-viscosity grades (e.g., CAB-551-0.01) enable high-solids, low-VOC formulations without compromising flow, supporting modern environmental compliance. High-viscosity grades (e.g., CAB-381-20) provide superior rheological control and sag resistance, ensuring consistent film build even on vertical surfaces.   Ⅲ. Which CAB grade is right for your automotive application? One table tells it all. The table below outlines the most commonly used grades and their selection criteria for typical automotive coating scenarios:   Application Scenario Recommended Grade Key Advantages & Critical Data Typical Use Primer / Metallic Paint CAB-381-0.5 Versatile First Choice. Butyryl content 38%, balanced viscosity, offering good hardness, compatibility, and pigment orientation. Improves parallel alignment of aluminum and pearlescent pigments, enhancing metallic effect and flop index. CAB-321-0.1 Specialized for Re-solvent Resistance. Butyryl content 32.5%, low molecular weight, excellent re-solvent resistance. Protects the basecoat layer from solvent penetration by the clearcoat, preventing color mottling. CAB-381-2 Higher Hardness Control. Higher viscosity, provides superior film hardness and pigment orientation control. Used in basecoats or intermediate coats requiring higher hardness. Refinish / General Modification CAB-551-0.01 Ultra-Low Viscosity Leveling Agent. Lowest Tg, excellent compatibility. Significantly improves leveling, reduces cratering, and shortens tack-free time. Often used as a modifying additive. CAB-551-0.2 High-Compatibility Modifier. High butyryl content (~52%), good flexibility. Used in high-solids or UV-curable systems to improve flexibility and leveling. High-Durability Topcoat/Clearcoat CAB-553-0.4 High-Hydroxyl Crosslinkable Type. Alcohol-soluble, high hydroxyl content for crosslinking reactions. Provides high crosslink density, significantly enhancing chemical resistance and weatherability. Rheology Control / Sag Prevention CAB-381-20 High-Viscosity Rheology Modifier. High viscosity, primarily used as a rheological control agent. Adjusts paint viscosity to prevent sagging during vertical or thick-film application, improving workability. Automotive Plastic Component Coatings CAB-531-1 High Flexibility. High butyryl content (~50%), adapts to plastic deformation without excessive plasticizers. Used for coatings on bumpers, interior parts, and other plastic substrates, providing good flexibility and adhesion.     Ⅳ. Critical Practical Formulation Tips   Blending is Standard PracticeIn actual formulations, to simultaneously meet leveling, sag control, and hardness requirements, grades with different viscosities are often blended. For example, use CAB-381-0.5 for primary performance, with a small addition of CAB-381-20 to adjust viscosity and prevent sagging.   Solvent Selection and Dissolution Safety CAB is generally readily soluble in esters (e.g., butyl acetate) and ketones. To avoid precipitation, it is recommended to first dissolve the CAB thoroughly in strong solvents before adding hydrocarbon diluents. A classic dissolution formula is: 50% Butyl Acetate / 35% Xylene / 15% Isobutanol.   Moisture Prevention is CrucialCAB powder is hygroscopic. For moisture-sensitive polyurethane systems, dry the CAB or azeotropically dehydrate it with solvents before use to prevent bubbling in the film. Summary The core logic for selecting CAB is: Identify your formulation's primary objective (metallic orientation, fast drying, re-solvent resistance, or rheology control?), then understand the three key parameters of the grade (butyryl content, hydroxyl content, viscosity), and finally make the choice based on your specific application scenario. There is no "universal grade," but by following this systematic comparison and utilizing blending techniques, you can develop automotive coating solutions with excellent performance and processability. Welcome to contact us for CAB grade selection recommendations and testing methods.  

In furniture finishing and wood coating formulations, cellulose acetate butyrate (CAB) has long been recognized as a high-performance additive. It promotes faster solvent release, reduces drying time, improves flow and leveling, and enhances gloss, scratch resistance, and overall film appearance. However, achieving these benefits depends on selecting the right CAB grade for your formulation.   Among the various CAB grades, which grade is the best fit for wood coatings? Instead of focusing on automotive applications, this guide takes a practical look at the performance requirements of wood finishes and explains how to choose the most suitable CAB grade for your specific needs.     I. Three Core Priorities for CAB in Wood Coatings In wood coating formulations, CAB is typically added to address three key challenges: Slow drying—especially in high-humidity environments or thick-film applications, where tack-free and hard-dry times directly impact production efficiency Poor leveling—brush marks, orange peel, and cratering compromise furniture appearance and tactile quality Inadequate film flexibility or hardness—films that are too brittle tend to crack, while those too soft lack scratch resistance Different CAB grades vary significantly in these three aspects due to differences in viscosity, butyryl content, and hydroxyl content.   II. Practical Roles of Common CAB Grades in Wood Coatings 1. CAB-381-0.5 — The Versatile All-Rounder This is the most common entry-level choice in wood coating formulations. It strikes an excellent balance between compatibility and viscosity, improving leveling while effectively promoting solvent release and shortening drying time. Best for: General-purpose wood coatings, including clear coats, pigmented finishes, and sealers Key value: Reliable performance with no major weaknesses Not ideal for: Systems demanding extreme hardness or ultra-fast drying   2. CAB-381-2 — Top Choice for High-Hardness Topcoats Compared to 381-0.5, CAB-381-2 has higher viscosity and delivers noticeably better surface hardness and scratch resistance after film formation. Best for: Topcoats for dining tables, coffee tables, flooring, and other applications requiring wear and scratch resistance Key value: Enhances film hardness while maintaining good pigment orientation control Note: Higher viscosity requires appropriate solvent adjustments in formulation   3. CAB-381-20 — The Rheology Modifier Expert This is not a primary film-forming resin but a rheology modifier. Its high viscosity effectively prevents sagging during thick-film or vertical-surface applications. Best for: High-build topcoats and vertical surface wood finishing Key value: Provides thickening and anti-settling properties with minimal impact on other film performance attributes   4. CAB-381-0.1 — Low-Viscosity Fast-Dry Assistant With extremely low viscosity, even small additions significantly reduce system viscosity, improve leveling, and accelerate surface drying. Best for: High-speed production lines requiring rapid layer stacking, or viscosity adjustment in high-solids systems Key value: Boosts application efficiency without sacrificing solids content   5. CAB-551-0.2 — High-Compatibility "Modifier Master" With high butyryl content, this grade offers exceptional compatibility with major wood coating binders including alkyd, polyurethane, and acrylic resins. As a modifier, it improves leveling, shortens drying time, and significantly reduces film shrinkage stress, lowering the risk of stress-induced cracking. Best for: Compatibility adjustment in complex resin systems, premium matte topcoats Key value: Enhances system stability while imparting better film flexibility   6. CAB-551-0.01 — Extreme Fast-Drying Solution Ultra-low viscosity and excellent compatibility make this grade highly effective at accelerating solvent release and shortening tack-free time. Best for: Quick-repair coatings, low-temperature curing systems, high-efficiency mass-production finishing lines Key value: Noticeable drying speed improvement with maintained leveling performance      III. Quick Selection Table for Wood Coatings Priority Need Recommended Grade Core Value General-purpose, balanced performance CAB-381-0.5 Versatile and reliable, lowest risk High hardness, scratch resistance CAB-381-2 Significant topcoat hardness improvement Thick-film anti-sagging CAB-381-20 Rheology control for vertical applications Fast drying, production line efficiency CAB-381-0.1 / 551-0.01 Shortens cycle times Complex resin system compatibility CAB-551-0.2 Excellent compatibility, reduces cracking risk     IV. Common Pitfalls: 3 Mistakes to Avoid When Selecting CAB for Wood Coatings Mistake #1: Higher viscosity is always better. High-viscosity grades like CAB-381-20 work well as rheology modifiers, but using them as the primary resin actually increases application viscosity and impairs leveling. Mistake #2: The 551 series can fully replace the 381 series. While 551 offers superior compatibility, it falls short of the 381 series in hardness enhancement and pigment orientation. Treat them as complements, not substitutes. Mistake #3: More CAB means faster drying. Excessive addition can make the film brittle and compromise intercoat adhesion. We recommend starting at 3%–8% of total formulation weight and conducting gradient tests.     The Best CAB Is the One That Fits Your Formulation As a professional Cellulose Acetate Butyrate (CAB) supplier in China, we have been serving the global coatings industry since 2014. Our manufacturing facility covers 54,500 m², is certified to ISO 9001, ISO 14001, ISO 45001, and holds EU REACH registration. With an annual production capacity of 10,000 tons of CAB and 6,000 tons of Cellulose Acetate (CA), we ensure a stable and reliable supply to customers worldwide.     Selecting the right CAB grade is one of the most effective ways to optimize wood coating performance. Whether you are developing a new wood coating formulation or optimizing an existing system, we are committed to providing reliable products, professional technical support, and customized formulation recommendations to help you achieve the ideal balance of performance, processing efficiency, and cost.

In the field of gold mining and metallurgy, how to efficiently and cost-effectively "capture" gold and silver from cyanide solutions is the core factor that determines the overall profitability of a project. Among the various gold recovery methods, the Merrill–Crowe process stands out for its exceptionally high precipitation efficiency and mature industrial application, remaining the preferred choice for large-scale gold and silver mines worldwide.   This article takes you through the chemical principles of the Merrill–Crowe process and explains why high-purity zinc dust is the undisputed "heart" of this flowsheet.    What Is the Merrill–Crowe Process? In simple terms, the Merrill–Crowe process is a hydrometallurgical method that uses zinc dust cementation to precipitate precious metals (gold and silver) from alkaline cyanide solutions. Invented in the late 19th century by Charles Washington Merrill and Thomas B. Crowe, this process has stood the test of time for over a century, thanks to its stable operation and high recovery rates.   The basic flowsheet consists of the following key steps: 1. Clarification of Pregnant Solution: The gold-bearing solution (pregnant solution) from the leaching circuit is passed through filtration equipment to remove suspended solids, ensuring a clear solution.   2. Vacuum Deoxygenation: This is a critical step! Dissolved oxygen consumes zinc dust and reduces precipitation efficiency. Therefore, the solution must be deoxygenated in a vacuum deaerating tower.   3. Zinc Dust Addition and Cementation: High-purity zinc dust is precisely metered into the deoxygenated pregnant solution to initiate the displacement reaction.   4. Pressure Filtration and Recovery: The mixture containing gold and silver precipitates enters a plate-and-frame filter press, producing a high-grade gold sludge, which is then sent for refining.   The Core Chemistry: How Does Zinc Dust "Capture" Gold? The chemical foundation of the Merrill–Crowe process is an electrochemical displacement reaction. Because zinc is more reactive (more negative electrode potential) than gold and silver, zinc dust loses electrons to become zinc ions (Zn²⁺), while gold ions (Au⁺) or silver ions (Ag⁺) in the solution gain electrons and are reduced to metallic form, precipitating onto the zinc particles.   Main reaction equation (using gold as an example):Zn + 2NaAu(CN)₂ → Na₂Zn(CN)₄ + 2Au↓   However, actual production is not always this ideal. If zinc dust is of insufficient purity or has uneven particle size, side reactions (such as zinc reacting with water to produce hydrogen gas) can occur. This leads to a sharp increase in zinc consumption and may form colloidal substances that are difficult to filter.   The Key to Process Success: High-Performance Zinc Dust In the Merrill–Crowe flowsheet, the quality of zinc dust directly determines precious metal recovery rates, filtration efficiency, and overall operating costs. Not all zinc dust is suitable for this application. Zinc dust specifically engineered for this demanding process must possess the following characteristics:   1. High Purity (≥99% Total Zinc) Impurities—especially lead, iron, and cadmium—can create micro-galvanic cells on the zinc particle surface, increasing unnecessary zinc consumption. More importantly, low impurity content ensures a clean cementation reaction, preventing contaminants from interfering with subsequent gold sludge refining.   2. Consistent Particle Size Distribution (e.g., 325 Mesh Grade) Particles that are too large have low specific surface area, resulting in slow reaction rates and incomplete gold precipitation. Particles that are too fine, while reactive, tend to clog filter cloths and reduce filter press efficiency. A stable particle size distribution (e.g., 95% passing through a 45-micron sieve) is the key to balancing reaction kinetics and solid-liquid separation performance.   3. High Specific Surface Area and Reactivity Zinc dust produced via specialized atomization or distillation-condensation processes features a thin surface oxide layer and a porous microstructure. This morphology imparts high surface activity, significantly accelerating the kinetics of gold precipitation and ensuring complete precious metal recovery within a very short residence time.   4. Excellent Flowability In large-scale industrial automated dosing systems, the flowability of zinc dust determines the stability and accuracy of feed rates. Poor-flowing powders tend to bridge or clog feeding equipment, causing fluctuations in zinc addition and compromising recovery stability.   Technical Data Interpretation Taking the industry-leading AAB Group ZP 325G high-purity zinc dust as an example, its technical specifications tailored for the Merrill–Crowe process demonstrate the benchmark for quality zinc dust: Metallic Zinc ≥96.0%: High active content ensures strong displacement driving force. Residue on 45µm Sieve ≤0.05%: Strict compliance with the 325-mesh standard ensures neither gold loss nor filter cloth blockage. Lead, Iron, and Cadmium Content All ≤0.01%: Ultra-low impurity levels are the guarantee for producing high-purity gold sludge and simplifying the refining process.   If you are operating a Merrill–Crowe gold recovery circuit, now is the time to evaluate the quality and performance of your zinc dust. A small upgrade in reagent selection can deliver substantial gains in precious metal recovery, process stability, and operational profitability—making high-performance zinc dust one of the most cost-effective investments in your entire refining process.

In 2021, several long-term clients in the automotive coatings industry approached us with a challenge: they wanted a high-end metallic nano titanium dioxide for their automotive paints, aiming to match the performance of leading global brands such as TAYCA (Japan) and Venator (USA).   Rising to the challenge, China AAB Industry Technology Group leveraged China’s complete and advanced industrial chain, supported by globally leading automotive metallic paint factories. Partnering with a top university in Nanjing, the company spent 5 years on research, development, and market testing, resulting in the launch of four high cost-performance nano titanium dioxide products: MT-5008HD, MT-7008HB, RM-2008H and RM-530L.     Key Features of Our Micro Titanium Dioxide 1. Distinctive Flip-Flop Effect Angle-dependent color variation: Delivers a flip-flop effect value of 10–35, producing noticeable color shifts at different viewing angles. Enhanced visual appeal: Imparts depth, texture, and a metallic luster to coatings, elevating product aesthetics and quality.   2. Superior Weather and Chemical Resistance & Durability Anti-chalking and extended lifespan: Resists chalking even after prolonged outdoor exposure, protects substrates, and extends coating service life beyond 10 years. Harsh environment resistance: Withstands UV radiation, moisture, temperature fluctuations, and other challenging conditions. Chemical and thermal stability: Rutile crystal structure ensures excellent resistance to acids, alkalis, chemical attack, and high-temperature processing.   3. Strong UV Shielding Capability High UV absorbance: Achieves UV absorption values from 1.0 to 4.0, effectively protecting against harmful radiation. Coating protection: Prevents yellowing, chalking, and cracking of resin binders caused by UV degradation.   4. Self-Cleaning Superhydrophilic surfaces: TiO₂ films prevent water droplet formation, allowing rainwater or cleaning to remove contaminants, keeping surfaces clean and clear.   5. Excellent Dispersibility Seamless integration: Narrow particle size distribution combined with Zr+Al inorganic surface treatment enables easy incorporation into various resin systems.     Why China AAB Industry Technology Group? Strength What It Means for You   Complete local industrial chain Stable supply, shorter lead times, and greater supply chain security   Automotive paint industry DNA Our technology is shaped by real-world requirements from leading metallic paint systems   University-backed R&D Five years of focused development with Nanjing-based academic partners   Four proven products Ready for automotive OEM, refinish, industrial coatings, and beyond     Conclusion As a professional manufacturer specializing in nano titanium dioxide, China AAB Industry Technology Group is redefining the global standard for high-performance, cost-effective micro- and nano-scale titanium dioxide. With distinctive optical effects, durability, UV protection, self-cleaning, and excellent dispersibility, AAB’s products have already passed rigorous customer validation and are now fully integrated into their production lines, proving their reliability and performance in real-world applications. This makes AAB the trusted and proven partner for the automotive coatings industry worldwide.

Nano titanium dioxide (Nano TiO₂) is a form of titanium dioxide with particle sizes ranging from 1 to 100 nanometers. Its ultrafine particles give it unique optical, chemical, and functional properties, enabling applications in areas where conventional TiO₂ cannot meet the requirements. With advances in nanotechnology, surface modification, and composite processing, the applications of nano TiO₂ are continuously expanding—from everyday consumer products to high-end manufacturing and environmental protection. Due to its ultrafine particle size, photocatalytic activity, and high surface area, nano titanium dioxide is transitioning from a traditional pigment to a frontier functional material. Whether in environmental protection, new energy, or high-end manufacturing, nano TiO₂ demonstrates tremendous application potential. As technology matures and costs decrease, nano TiO₂ is expected to play an increasingly important role in industry, daily life, and scientific research.   Key Functions of Nano Titanium Dioxide Nano titanium dioxide (Nano TiO₂), with particle sizes below 100 nanometers, a high specific surface area, and a white loose powder appearance, possesses a wide range of functional applications. Its main functions can be summarized into eight categories: Antibacterial Function: Under ultraviolet light, nano TiO₂ generates reactive radicals that effectively kill bacteria and pathogens. It is widely used in water treatment, air purification, and antibacterial coatings for hospitals, operating rooms, and residential spaces, providing self-cleaning, anti-fouling, and deodorizing effects. UV Protection: Nano TiO₂ can absorb, reflect, and scatter ultraviolet rays while remaining transparent to visible light. It acts as a physical and chemical UV blocker in sunscreens, food packaging, coatings, and plastic fillers, offering stable, non-toxic protection.  Photocatalytic Function: Activated by light, nano TiO₂ decomposes organic pollutants such as formaldehyde and some inorganic substances, purifying air and surfaces, and enabling self-cleaning materials.  Anti-Fog and Self-Cleaning: TiO₂ films exhibit superhydrophilicity, preventing water droplet formation. Rainwater or cleaning can remove contaminants, keeping glass, ceramics, and tiles clean and clear.  New Energy Materials: In lithium-ion batteries and solar cells, nano TiO₂ improves capacity, charge/discharge performance, cycling stability, and photovoltaic conversion efficiency, while reducing costs and extending service life. Textile Sizing Replacement: Nano TiO₂ can replace traditional PVA sizing, enhancing yarn performance, reducing environmental impact, lowering production costs, and simplifying processing. High-End Automotive Coatings: When combined with metallic or pearlescent pigments, nano TiO₂ produces multi-angle color-changing effects, pearl luster, and metallic sheen, enhancing the visual quality of automotive paints. Other Functions: Nano TiO₂ can degrade certain plastics and harmful gases, offering potential in environmental purification and the development of high-performance composite materials.   Thanks to these versatile functions, nano titanium dioxide is transitioning from a traditional pigment to a functional material, with wide applications in protection, environmental sustainability, new energy, textiles, and high-end coatings. Its research and utilization continue to drive technological and industrial advancements. Applications of Kmeris® MT-5008HD Nano Titanium Dioxide in Industrial Coatings Kmeris® MT-5008HD is a high-performance nano titanium dioxide with ultra-fine particle size, large specific surface area, and a white loose powder appearance. It combines photocatalytic activity, UV resistance, and self-cleaning properties, making it ideal for high-end coating applications.   1. Automotive CoatingsIn automotive paints, MT-5008HD can be combined with metallic or pearlescent pigments to achieve multi-angle color-changing effects and pearlescent luster, enhancing the metallic sheen and depth of the car finish. Nano TiO₂ films exhibit strong superhydrophilicity and long-lasting stability under light, making them highly effective for anti-fog applications in automotive use. When applied to car side mirrors or windshields, moisture in the air does not condense into scattered droplets; instead, it forms a uniform water film. This prevents light scattering and maintains clear visibility, significantly enhancing driving safety.   Additionally, the photocatalytic properties of nano TiO₂ can decompose organic contaminants on vehicle surfaces, such as oil, dust, and bacteria. Under sunlight, these pollutants are oxidized into harmless CO₂ and H₂O and can be easily washed away by rain, achieving a self-cleaning effect.   This functionality is not limited to mirrors and windshields; it can also be applied to headlights, windows, and car paint surfaces, reducing cleaning frequency, lowering maintenance costs, and maintaining a bright, clean appearance. The anti-fog and self-cleaning properties of nano TiO₂ make it an ideal material for high-end automotive coatings and functional glass.   2. Metallic CoatingsMT-5008HD can be used in premium metallic paints, where it protects metal surfaces from photochemical oxidation and corrosion by scattering and absorbing UV light. Its ultra-fine particle size ensures smooth and uniform paint films, providing excellent visual effects and coating durability.   3. Architectural Exterior CoatingsIn building exterior paints, MT-5008HD forms UV-resistant, anti-fouling, and self-cleaning coatings. The photocatalytic activity of nano TiO₂ decomposes organic pollutants attached to the surface, which can then be washed away by rain, reducing maintenance costs and maintaining vibrant exterior colors over time.   4. Aircraft Skin PaintsAircraft coatings require exceptional durability and protection. MT-5008HD nano TiO₂ absorbs and scatters UV rays, reducing coating aging, enhancing surface wear resistance, and improving corrosion protection. Its photocatalytic self-cleaning function also helps maintain clean aircraft surfaces, lowering maintenance frequency and extending service life.   We warmly invite you to visit our factory to see our production capabilities firsthand and explore the high-quality applications of our products. For more detailed information about Kmeris® MT-5008HD Nano Titanium Dioxide or to discuss how it can meet your specific needs, please do not hesitate to contact us. We look forward to collaborating with you and helping you unlock the full potential of nano TiO₂ in your applications.

Titanium dioxide (TiO₂) is a common white inorganic pigment widely used in coatings, plastics, cosmetics, and food. With the development of nanotechnology, Micro titanium dioxide (TiO₂) has emerged. Although both are chemically TiO₂, they differ significantly in structure, performance, and applications.   1. Particle Size and Structural Differences Conventional Titanium Dioxide: Particle size is usually above 200–300 nanometers, falling in the micron range. The larger particles have a relatively smaller surface area. Nano Titanium Dioxide: Particle size is usually below 100 nanometers, sometimes in the range of 10–50 nanometers. These extremely small particles have a greatly increased surface area, exhibiting pronounced nanoscale effects. This difference in particle size leads to notable variations in optical properties, chemical activity, and dispersibility.   2. Optical Performance Differences Opacity and Whiteness: Conventional TiO₂ provides excellent opacity due to its high refractive index and suitable particle size. Nano TiO₂ has slightly lower opacity because its particles are smaller than the wavelength of visible light, making it suitable for transparent or semi-transparent coatings. Optical Effects: Nano TiO₂ has strong photocatalytic activity under ultraviolet light and can effectively absorb and scatter UV rays, making it ideal for sunscreens and self-cleaning materials.   3. Chemical Activity and Functional Differences Conventional TiO₂: Chemically stable and unlikely to trigger photocatalytic reactions. Nano TiO₂: Due to its large surface area and abundant reactive sites, it readily generates free radicals under light. This makes it useful for self-cleaning coatings, air purification, and degradation of organic pollutants.However, this high activity may pose potential risks to organic materials or biological tissues, which is why surface modification (e.g., coating with silica or alumina) is often applied to reduce such risks. 4. Dispersibility and Processing Performance Conventional TiO₂: Larger particles tend to settle or agglomerate and require mechanical stirring or dispersants to maintain uniformity. Nano TiO₂: Small particle size and high surface energy make it easier to form stable dispersions, but it also tends to agglomerate, requiring surface treatment or dispersants to maintain even distribution.   5. Application Differences Feature Conventional TiO₂ Nano TiO₂ Opacity High Lower, suitable for transparent applications UV Absorption Moderate High, ideal for sunscreens and photocatalysis Photocatalytic Activity Low High, suitable for self-cleaning and environmental purification Cosmetics Mainly opaque coverage Sunscreens, transparent foundations Coatings Interior/exterior paints, plastic fillers Functional coatings, antibacterial coatings, photocatalytic coatings, Self-cleaning coatings   Although nano titanium dioxide and conventional titanium dioxide share the same origin, they have diverged into two distinct technological paths: one as a “pigment” and the other as a “functional material.” Understanding the fundamental differences between the two is the first step toward scientifically selecting materials and precisely developing products. With continuous advances in surface modification and composite technologies, the application prospects of nano titanium dioxide in environmental protection, new energy, and high-end manufacturing are becoming increasingly broad.

High-pigment carbon black and organic pigments are notoriously difficult to disperse—a challenge that is especially common in high-end automotive and industrial coatings. This often leads to increased system viscosity, higher grinding costs, reduced storage stability, and even defects in the dry film such as hue deviation (e.g., reddish carbon black), floating, flooding, and gloss reduction. Our product offers an effective and reliable solution to these issues.   When dealing with high surface area carbon black and structurally complex organic pigments, dispersants often face a dilemma: they must reduce system viscosity while simultaneously maintaining color stability. To meet these demanding requirements, our KBS-6175 dispersing additive  features a unique polyurethane copolymer structure and provides a systematic solution. It is analogous to BYK-163 and EFKA-4063. It goes beyond traditional additive functionality by fundamentally restructuring pigment dispersion behavior through a dual stabilization mechanism combining steric hindrance and electrostatic repulsion.   How Does KBS-6175 to Achieve a Balance Between Viscosity Reduction and Color Stability?  1. Steric Hindrance BarrierLong-chain polymers form a robust three-dimensional protective layer on the pigment surface, acting like a physical scaffold that separates adjacent particles and effectively prevents flocculation and agglomeration caused by Brownian motion.   2. Electrostatic RepulsionUniform surface charges are imparted to pigment particles, creating a secondary “safety lock” through electrostatic repulsion. This ensures system stability even under high solid content or high shear conditions. This “physical + chemical” dual stabilization mechanism effectively resolves the common issue of co-flocculation in multi-component systems, laying a solid foundation for long-term storage stability of coatings. Why Choose Our KBS-6175? 1. Enhances Blackness QualityKBS-6175 is specifically designed for high-pigment carbon black. After dispersion, the black paste exhibits a clean, intense bluish undertone, eliminating the common reddish or yellowish hues found in the industry. This ensures precise color matching and high-end coating appearance.   2. Shortens Grinding Time and Production CycleKBS-6175 effectively reduces slurry viscosity during grinding, improving efficiency and speed. Under the same energy input, it enables higher output. It also supports high pigment loading formulations, shortening production cycles and delivering direct economic benefits.   3. Improves Gloss, Color Saturation, and TransparencyOnly fully dispersed pigments can deliver optimal performance. With KBS-6175, coatings show significant improvements in gloss, color saturation, transparency, and hiding power, resulting in richer and more durable color performance.   4. Broad Application CompatibilityKBS-6175 is highly compatible with two-component polyurethane (2K PU) systems and baking-curing systems. It performs reliably across automotive coatings, industrial anti-corrosion coatings, architectural coatings, and wood coatings, supporting the development of diverse product lines.   Choose our KBS-6175 to effectively solve your coating challenges such as difficult dispersion of high-pigment carbon black, poor stability of organic pigments, and issues like floating and flooding. Feel free to contact us for the TDS and application guidelines.

Currently, there are only a few systematic studies comparing the coating performance of TGIC and HAA, two types of outdoor curing agents. In this study, the coatings made with different curing agents were tested using methods such as water boiling, high-temperature baking, solvent wiping, and accelerated weathering.   The results showed that when the same polyester resin was cured with TGIC and HAA respectively, the polyester-TGIC coating performed better in water boiling resistance and yellowing resistance under high-temperature baking. In contrast, the polyester-HAA coating showed better resistance to solvent wiping and better weathering performance   As a type of polymer material, the performance of thermosetting powder coating primarily depends on the structure and aggregation state of the resin used. The curing agent plays a key role in determining its aggregation state.   Triglycidyl isocyanurate (TGIC) and hydroxyalkylamide (HAA) are the two mainstream curing agents for outdoor thermosetting powder coatings. Powder coatings cured with TGIC typically achieve excellent light and heat stability, abrasion resistance, and outstanding weathering performance. As a result, TGIC has remained highly favored since its introduction.   However, as people's living standards have risen and environmental awareness has grown, TGIC has faced increasing scrutiny due to its inherent toxicity and the environmental harm caused during its manufacturing process. As early as 1998, Europe and Australia had already banned the use of TGIC.   As the most ideal alternative to TGIC, HAA has developed rapidly in the industry since its successful development. In 2003, it officially replaced TGIC to become the world's largest curing agent for weather-resistant powder coatings. Except for a few properties where it does not perform as well as TGIC-cured powder coatings, the overall performance of powder coatings cured with HAA is comparable to that of TGIC-cured systems.   This study focuses on the aging performance of outdoor powder coatings. Powder coatings were prepared using TGIC and HAA respectively, and the advantages and disadvantages of each in terms of aging performance were compared and investigated.     1. Experimental Section 1.1 Experimental Raw Materials Super weather-resistant polyester resin (hereinafter referred to as polyester); curing agent TGIC; curing agent HAA; titanium dioxide; barium sulfate; leveling agent; benzoin; gloss enhancer.     1.2 Powder Coating Preparation   Table 1 Formulation of Powder Coatings Raw Material TGIC-type Coating Formulation /g HAA-type Coating Formulation /g Polyester Resin 279 285 TGIC/HAA 21 15 Titanium Dioxide (TiO₂) 102 102 Barium Sulfate (BaSO₄) 90 90 Leveling Agent 4 4 Benzoin 2 2 Brightener — 2.2   Powder coatings were prepared according to the basic formulation shown in Table 1. The process steps were as follows: batching → premixing → extrusion → tableting → grinding → sieving → finished product. The prepared powder coatings were applied by electrostatic spraying and then cured at 200°C for 10 minutes to obtain the powder coatings.   1.3 Experimental Testing and Conditions 1.3.1 Isothermal Curing Test Isothermal curing tests of the powder coatings were conducted using differential scanning calorimetry (DSC). The test conditions were as follows: N₂ as protective gas at a flow rate of 50 mL/min; heating rate of 300 K/min, rapidly heating to 200°C and holding for 20 min.   1.3.2 Water Boiling Test Water boiling tests were carried out using a sterilizing pressure cooker with deionized water at 120°C. After the water boiling test, the coating surface was wiped dry, and the color difference and gloss were measured.   1.3.3 Water Absorption Rate Test The water absorption rate of the coating was calculated based on the mass difference before and after water absorption. The mass of the coating after vacuum drying was recorded as m₁, and the mass after immersion in water or boiling, with the surface wiped dry with paper, was recorded as m₂. The water absorption rate ω = [(m₂ − m₁)/m₁] × 100%.   1.3.4 Baking Test Baking tests were conducted using a forced-air oven, with a baking time of 2 hours. After baking, the color difference and gloss of the coating were measured.   1.3.5 Solvent Wiping Test The powder coating was sprayed onto an aluminum substrate and cured at 200°C for 10 minutes. A methyl ethyl ketone (MEK) instrument wiping test was performed, with a load of 1000 g on the test panel and a wiping frequency of 50 times per minute. The number of wipes required to expose the substrate was recorded. Each coating thickness was wiped three times, and the average of the three results was taken.   1.3.6 Accelerated Artificial Weathering Test Accelerated artificial weathering tests were conducted using a QUV-313 tester. The test conditions were as follows: irradiance of 0.71 W/m², 4 hours of light exposure at 60°C, followed by 4 hours of condensation at 50°C. After the test, the color difference and gloss of the coating surface were measured.   1.3.7 Coating Thickness Test The coating thickness test was carried out in accordance with GB/T 4957.   1.3.8 Coating Gloss Test The coating gloss test was carried out in accordance with GB/T 9754, measured at a 60° incident angle.   1.3.9 Coating Color Difference Test The coating color difference test was carried out in accordance with GB/T 11186.2 and GB/T 11186.3.     2. Results and Discussion 2.1 Isothermal Curing Test Figure 1 shows the isothermal curing process curves of polyester-TGIC and polyester-HAA at 200°C.   Figure 1 shows the isothermal curing process curves of polyester-TGIC and polyester-HAA at 200°C. The experimental results show that the time to reach the maximum reaction rate for polyester-TGIC during isothermal curing was 21 seconds, while for polyester-HAA it was 15 seconds. This indicates that the reaction between polyester and TGIC is faster. Meanwhile, as can be seen from the curing reaction degree curve (Figure 2), at 600 seconds, the reaction degree of polyester with TGIC reached 98.82%, while that of polyester with HAA reached 94.60%. At 200°C, within the same period, the reaction between polyester and TGIC was faster and achieved a higher reaction degree compared to that between polyester and HAA. This may be due to the presence of a curing accelerator in the polyester that promotes the reaction with TGIC, while this accelerator shows no significant accelerating effect on the reaction between polyester and HAA. Overall, under the curing condition of 200°C for 10 minutes, the difference in reaction degree between polyester-TGIC and polyester-HAA is relatively small, which has little effect on the overall performance differences of the coatings.   2.2 Water Resistance Test   Figure 3 shows the changes in color difference and gloss retention of polyester-TGIC coating and polyester-HAA coating under different water boiling times.   As can be seen from Figure 3, with increasing water boiling time, the color difference of the coatings increased while the gloss retention decreased. It can also be observed that the changes in color difference and gloss retention of the polyester-HAA coating were greater than those of the polyester-TGIC coating. In particular, the gloss retention of the polyester-HAA coating showed a sharp decline.   As water boiling time extended, the surface of the polyester-HAA coating exhibited severe loss of gloss and even chalking. This phenomenon may be attributed to the larger free volume of the polyester-HAA coating at 120°C, making it easier for water to penetrate into the coating and react with it during the water boiling process.   In addition, to compare the affinity between the coatings and water, the water absorption rates of the coatings were investigated under different conditions.   Table 2 shows the water absorption rates of the coatings at room temperature and after water boiling at 120°C for 2 hours. It can be seen that at room temperature, the water absorption rate of the polyester-TGIC coating was slightly higher than that of the polyester-HAA coating. Table 2 Water absorption of coatingunder different conditions Coating Polyester-TGIC Polyester-HAA Water absorption (room temperature (~30℃)) 1.53% 0.86% Water absorption(120℃/2h) 9.54% 31.2%  After water boiling at 120°C for 2 hours, the water absorption rates of both coatings changed significantly compared to those at room temperature. After water boiling, the water absorption rate of the polyester-HAA coating increased sharply and was much higher than that of the polyester-TGIC coating.   The factors causing the changes in water absorption under different conditions may be due to the fact that at room temperature, the coating structure remains dense, making it difficult for water to adsorb and penetrate into the coating, resulting in relatively low water absorption rates for both coatings. However, under water boiling conditions at 120°C, the coating structure undergoes significant changes, allowing a large amount of water to enter the coating interior, leading to a sharp increase in water absorption.   For polymers, below the glass transition temperature, the internal structure exhibits rigid "voids"; above the glass transition temperature, the internal structure exhibits flexible "free volume."   The difference in water absorption between the polyester-TGIC coating and the polyester-HAA coating at 120°C may be due to the greater flexibility of the polyester-HAA coating compared to the polyester-TGIC coating. The polyester-HAA coating has a larger free volume at 120°C, allowing it to accommodate more water.     2.3 Heat Resistance Test     Figure 4 shows the changes in color difference and gloss retention of the polyester-TGIC coating and polyester-HAA coating after baking at different temperatures.   It can be observed that as the baking temperature increased, the color difference of both coatings increased, and the color difference change of the polyester-HAA coating was significantly greater than that of the polyester-TGIC coating.   This is mainly due to the presence of nitrogen elements in HAA itself and during its production process, which are prone to discoloration, as well as nitrogen-containing impurities remaining from the HAA manufacturing process. Under high-temperature conditions, a series of reactions occur, generating chromophoric groups that cause yellowing.   During the baking process, the gloss retention of the polyester-TGIC coating remained unchanged initially, then showed a sharp decline at 250°C. This was mainly due to secondary melting of the coating at 250°C, resulting in severe orange peel on the coating surface. In contrast, the gloss retention of the polyester-HAA coating remained unchanged or slightly increased under the same test conditions, mainly due to re-leveling of additives on the coating surface.   Comparing the experiments of polyester-TGIC and polyester-HAA coatings at different temperatures, it can be seen that the yellowing resistance of polyester-TGIC is far superior to that of polyester-HAA. However, at 250°C, the polyester-TGIC coating undergoes secondary melting, which severely compromises its normal use. Therefore, excessively high temperatures should also be avoided when using polyester-TGIC.     2.4 Solvent Resistance Test   Table 3 Solvent rubs for coating with different thickness Coating Polyester-TGIC Polyester-HAA Thickness (~45 μm) 17 28 Thickness (~55 μm) 33 38 Thickness (~65 μm) 40 41     2.5 Accelerated Artificial Weathering Test     Figure 5 shows the test results of polyester-TGIC and polyester-HAA coatings under different aging times. It can be seen that as the aging time increases, the color difference of the polyester-TGIC coating gradually increases while the gloss retention gradually decreases. Similarly, the color difference of the polyester-HAA coating also gradually increases and the gloss retention gradually decreases.   It can also be observed that at the same aging time, the changes in color difference and gloss retention of the polyester-HAA coating are smaller than those of the polyester-TGIC coating. This indicates that the weathering resistance of the polyester-HAA coating is superior to that of the polyester-TGIC coating.   Conclusion (1) When using TGIC and HAA to cure the same polyester resin respectively, the reaction between polyester and TGIC is faster than that between polyester and HAA. (2) The polyester-TGIC coating exhibits better water boiling resistance and yellowing resistance under high-temperature baking compared to the polyester-HAA coating. (3) The polyester-HAA coating exhibits better solvent wiping resistance and weathering resistance compared to the polyester-TGIC coating.

The ocean is a world of extraordinary biodiversity, nurturing over 8,000 species of plants and 59,000 species of animals. Among them, approximately 600 species of fouling plants and 18,000 species of fouling animals will take the hull of a ship as their attachment target. These fouling organisms each have their own characteristics: barnacles possess hard calcareous shells with extremely strong adhesion, capable of firmly attaching even at a ship speed of 10 knots; oysters and mussels are mollusks that grow rapidly, and the organic acids they secrete can corrode the steel plate; sea squirts and bryozoans are colonial organisms that tend to form thick fouling layers on the hull; algae such as green algae and brown algae rely on photosynthesis for growth and are mainly distributed near the waterline; in addition, bacterial slime, secreted by bacteria and diatoms, represents the initial stage of the fouling process, creating conditions for the subsequent attachment of larger organisms.   The impact of these fouling organisms is far greater than one might imagine: with just 5% hull fouling, fuel consumption increases by 10%. When fouling reaches 50%, fuel consumption surges by over 40%. On a global scale, if the world's fleet had an average fouling level of 50%, an additional 7.06 billion tons of fuel would be burned each year, resulting in 210 million tons of excess carbon dioxide emissions. When a ship's hull becomes heavily encrusted with barnacles, oysters, and algae, it is like donning a suit of heavy armor—not only does sailing speed drop and fuel consumption soar, but even more troubling, the secretions from these organisms quietly corrode the steel, shortening the vessel's service life.   In the face of challenges posed by these "uninvited guests"—reduced speed, increased fuel consumption, and hull corrosion—humanity has never ceased its search for solutions. Today, we dive into the world of antifouling coatings on the hull, focusing on this unassuming layer of paint, to see how it has become a critical defense line in the struggle against marine organisms.   What is Antifouling Coating? Antifouling coating is a specialized coating applied over the anti-corrosion primer on the hull. It works by continuously releasing antifouling agents, forming a thin layer containing active ingredients at the interface between the seawater and the coating, killing or repelling the larvae and spores of marine organisms that attempt to attach. Maintaining the effectiveness of antifouling coatings throughout a ship's docking cycle of approximately five years presents a significant technical challenge.   1. Characteristics of Antifouling Coatings Antifouling effectiveness: Prevents marine organism attachment within a specified period Antifouling agent leaching: Continuous and stable release into seawater Water permeability: The coating film must have a certain degree of water permeability to maintain antifouling agent leaching Interlayer adhesion: Good bonding with the anti-corrosion primer, with mutual solubility between coating layers Resistance to seawater impact: No blistering or peeling during prolonged immersion Self-polishing property (modern types): Gradual dissolution of the coating film during navigation, resulting in an increasingly smooth surface   2. Composition of Antifouling Coatings Antifouling Agents: The core component, which must be slightly soluble in seawater and capable of killing or repelling marine organisms Traditional: Cuprous oxide, organotin (TBT), mercury oxide (banned), DDT (phased out) Modern: Copper pyrithione, zinc pyrithione, zineb, isothiazolone, etc. (low toxicity, environmentally friendly) Binders/Resins: Control the leaching rate of antifouling agents Soluble binders: Rosin (traditional), organotin copolymers (banned), acrylic copolymers (modern tin-free types) Insoluble binders: Asphalt, chlorinated rubber, acrylic resins, etc. Pigments: Improve mechanical properties and regulate leaching rate; commonly used are zinc oxide, iron oxide red, talc Solvents and Additives: Thixotropic agents, anti-settling agents, stabilizers, etc.   3. Antifouling Mechanism: How to Drive Away Uninvited Guests? The working mechanism of antifouling coating is as follows: when the coating film comes into contact with seawater, the antifouling agents (such as copper ions) gradually dissolve into the seawater, forming a thin active layer approximately ten to twenty microns thick on the coating surface, thereby repelling or killing the larvae and spores of marine organisms that attempt to attach.   The release rate of antifouling agents is measured by "leaching rate." Different antifouling agents require different leaching rates to remain effective: for copper ions, approximately 10 μg/(cm²·d); for organotin, only 1 to 2 μg/(cm²·d).   Control of the leaching rate is crucial—if the rate falls below the critical value, the antifouling effectiveness is lost; if it exceeds the critical value, it wastes the antifouling agents and shortens the coating's service life. Therefore, a high-performance antifouling coating must maintain a stable leaching rate slightly above the critical value throughout its service period, which can last several years.   Types of Antifouling Coatings: Five Generations from Traditional to Future In response to the challenge of marine fouling, antifouling coatings have undergone multiple technological iterations over the past several decades. From early traditional antifouling coatings, to the revolutionary organotin self-polishing coatings, to today's mainstream tin-free self-polishing systems, and even to future-oriented low-surface-energy non-toxic coatings—each technological breakthrough represents a pursuit of a better balance among antifouling effectiveness, service life, and environmental safety. This path of technological evolution also reflects humanity's deepening understanding of marine environmental protection.   First Generation: Conventional Types (Soluble / Contact / Diffusion Types) Antifouling Agents Soluble Type Antifouling Agents:Uses rosin as a soluble binder, with the entire paint film gradually dissolving in seawater, allowing antifouling agents to be continuously released.Disadvantages: High initial leaching rate, rapid decline in performance at later stages, and a service life of 1–3 years.   Contact Type Antifouling Agents:Uses an insoluble resin as the binder, with a very high content of antifouling agents (volume ≥ 52.4%). The particles are densely packed; as the surface layer dissolves, the inner agents are released through the voids.Service life: Can exceed 2 years.   Diffusion Type Antifouling Agents:Uses organotin compounds as antifouling agents (now phased out). Seawater penetrates the coating, causing it to swell, and the antifouling agents diffuse outward from the interior of the film.   Second Generation: Organotin Copolymer Self-Polishing (TBT-SPC) Antifouling Agents Developed in the 1970s, this was a groundbreaking innovation in antifouling technology. The organotin copolymer serves both as the antifouling agent and the binder. In seawater, it undergoes hydrolysis, enabling a steady release of organotin while the paint film gradually dissolves. As a result, the surface becomes increasingly smooth—this is known as the “self-polishing” effect.   Advantages: Stable leaching rate of antifouling agents, with a service life of up to 5 years Self-smoothing film reduces drag and saves fuel Resistant to alternating wet and dry conditions, suitable for use at the waterline Easy maintenance, allowing direct overcoating   Fatal Drawback:Organotin compounds are highly toxic to non-target marine organisms. They have been shown to cause imposex in gastropods and deformities in oysters, and can enter the human body through the food chain. In 2001, the International Maritime Organization (IMO) adopted the International Convention on the Control of Harmful Anti-Fouling Systems on Ships (AFS Convention), which led to a global ban on organotin-based antifouling paints. A complete prohibition came into effect on January 1, 2008.   Third Generation: Tin-Free Self-Polishing Antifouling Coatings (Mainstream Today) Developed as a replacement for TBT-based systems, these coatings mainly fall into three categories:   1. Hydration Type (CDP) Antifouling CoatingsUses rosin as a soluble binder, with hydrophobic resins controlling the release rate. The mechanism is as follows: rosin reacts with seawater to release biocides, while the surface hydrophobic resin forms a honeycomb-like structure. Under the scouring action of seawater, these structures break off, achieving “mechanical polishing.”Service life: Approximately 36 monthsFeatures: Lower cost, but forms a relatively thick leached (saponified) layer (~75 μm), requiring high-pressure freshwater washing during maintenance.   2. Hydrolysis Type (SPC) Antifouling CoatingsUses copper acrylate, zinc acrylate, or silyl acrylate copolymers as binders. These undergo hydrolysis or ion exchange in seawater, enabling a controlled and steady release of antifouling agents—achieving true “chemical polishing.”Features: Thin leached layer (~25 μm), excellent self-smoothing properties, and a service life of up to 60 months. Suitable for high-speed vessels (>20 knots). Zinc Acrylate Type Antifouling Coatings:Polymer–COO–Zn–X + Na⁺ → Polymer–COO⁻Na⁺ + Zn²⁺ + X⁻ Silyl Acrylate Type Antifouling Coatings:Polymer–COO–SiR₃ + Na⁺ + Cl⁻ → Polymer–COO⁻Na⁺ + R₃SiCl   3. Hybrid Type Antifouling CoatingsCombines CDP and SPC technologies, with a high solids content (~60%). The leached layer is about 45 μm thick, offering a service life of 36–60 months at a moderate cost.   Fourth Generation: Low Surface Energy (Non-Toxic) Antifouling Coatings This represents the most ideal antifouling approach: no release of any antifouling agents. By creating an ultra-low surface energy, the coating makes it difficult for marine organisms to attach, or prevents them from adhering firmly. Any attached organisms can be easily removed by water flow during vessel operation.   Mainstream Materials: Silicone resins (polydimethylsiloxane, PDMS) Fluorocarbon resins   Advantages: Completely non-toxic and environmentally friendly Antifouling service life of 5–10 years Lower dry-docking and maintenance costs   Limitations: Best suited for vessels operating at relatively high speeds (15–30 knots) High cost Complex application process Relatively poor adhesion   Latest Developments:Fluorinated polysiloxanes (such as PNFHMS and PTFPMS), which combine the low surface energy of fluorocarbons with the high elasticity of silicone materials.   Latest Standard for Ship Bottom Antifouling Coatings: GB/T 6822—2024 In 2006, China merged and revised GB/T 13351—1992 General Technical Conditions for Ship Bottom Anti-Rust Paints and GB/T 6822—1986 General Technical Conditions for Ship Bottom Antifouling Paints into GB/T 6822—2008 Antifouling and Anti-Corrosion Coating Systems for Ship Hulls. The newly updated standard, GB/T 6822—2024, specifies the following requirements for antifouling coatings: Compatibility with Anti-Corrosion Coatings:Includes shallow sea immersion tests, dynamic simulation tests, and cathodic protection compatibility tests. Antifouling Performance:Evaluated through shallow sea immersion testing. Toxicity Requirements:Must not contain asbestos or prohibited chemical substances. Application Properties:Suitable for high-pressure airless spraying, air spraying, roller coating, and brush application. Storage Stability: After 1 year of natural storage or 30 days of accelerated storage, the coating must be able to be uniformly mixed within 5 minutes.   Future Development Trends: Environmentally Friendly, Long-Lasting, and Low Surface Energy Advancement of Tin-Free Self-Polishing Coatings:Further optimization of copper/zinc/silyl acrylate copolymers to improve polishing stability and extend antifouling service life. Copper-Free Antifouling Coatings:Reduce the use of cuprous oxide and develop low-copper or copper-free systems based primarily on organic antifouling agents. Upgrading Low Surface Energy Coatings:Overcome the application challenges and poor adhesion of silicone-based coatings to expand their range of use. Biobased Antifouling Agents:Extract natural antifouling substances from marine plants and animals, such as capsaicin and eucalyptus extracts. Fiber Flocking Antifouling:Utilize micro-fiber structures to make it difficult for fouling organisms to attach. Smart Monitoring Coatings: Integrate sensors into coatings to provide real-time feedback on antifouling agent release status.   The development of marine antifouling coatings still faces multiple challenges. On one hand, a balance must be struck between antifouling effectiveness and ecological safety; on the other hand, it must adapt to variations in different marine environments, sailing speed conditions, and service cycles. From the rise and fall of organotin, to the emergence of tin-free self-polishing coatings, and the ongoing exploration of low-surface-energy coatings—each advancement represents a pursuit of more environmentally friendly and longer-lasting solutions. Therefore, future development directions will place greater emphasis on green environmental protection, high efficiency and longevity, as well as multifunctional integration—such as integrated coating systems that combine anti-corrosion, antifouling, and drag reduction properties.   Facing these multiple challenges in marine antifouling coatings—balancing ecological safety, environmental adaptability, and long-term performance—future technological breakthroughs rely on continuous innovation in core materials. China AAB Group stands at the forefront of the industry, offering a range of high-performance antifouling raw materials and solutions:   From Copper Acrylate Self-polishing Resin and Silyl Acrylate Self-polishing Resin (SPSi-A100), to high-efficiency antifouling agents such as Zinc Pyrithione (ZPT) , Copper Pyrithione Powder 98% (CPT-98) , and Copper Pyrithione Paste/Dispersion (CPT) , as well as the broad-spectrum fungicide DCOIT 98% —we are committed to providing stable quality and professional technical support, helping coating manufacturers develop high-performance antifouling coatings that combine environmental friendliness, long-lasting effectiveness, and multifunctional integration. Whether you are focused on optimizing traditional systems or pioneering next-generation green antifouling technologies, China AAB Group is your trusted partner. Please contact us to learn more about our popular products and join us in advancing marine antifouling coatings toward a greener, more efficient, and smarter future.