PBTC is a high-performance phosphonate-based scale and corrosion inhibitor widely used in daily chemical products due to its excellent chelation ability, thermal stability, and compatibility with other ingredients. Below are its primary applications in household and personal care products:
1. Laundry Detergents & Fabric Care
Function:
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Prevents scale buildup (e.g., CaCO₃, Mg²⁺) in washing machines and on fabrics.
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Enhances detergent efficiency by softening water (sequesters Ca²⁺/Mg²⁺), improving surfactant performance.
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Reduces fabric stiffness caused by mineral deposits.
Typical Dosage:
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0.1–0.5% in liquid/powder detergents.
2. Dishwashing Liquids & Cleaners
Function:
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Prevents lime scale on dishes, glassware, and dishwasher interiors.
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Improves foam stability in hard water by neutralizing metal ions.
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Protects stainless steel from corrosion (especially in automatic dishwashers).
Typical Dosage:
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0.05–0.3% in manual dishwashing liquids.
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0.2–0.8% in machine dishwasher detergents.
3. Personal Care Products (Shampoos, Shower Gels)
Function:
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Prevents soap scum (Ca/Mg fatty acid salts) in shampoos and body washes.
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Enhances lathering in hard water by reducing ion interference.
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Stabilizes formulations by chelating trace metals (Fe³⁺, Cu²⁺) that degrade fragrances or preservatives.
Typical Dosage:
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0.05–0.2% in shampoos and liquid soaps.
4. Household Surface Cleaners
Function:
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Removes hard water stains from tiles, faucets, and bathroom surfaces.
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Prevents scale redeposition after cleaning.
Typical Dosage:
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0.1–0.5% in bathroom/kitchen cleaners.
5. Advantages of PBTC in Daily Chemicals
| Property | Benefit |
|---|---|
| High Chelation | Binds Ca²⁺/Mg²⁺ more effectively than citrates or EDTA at low doses. |
| Thermal Stability | Stable in hot water (up to 100°C), suitable for dishwasher detergents. |
| pH Tolerance | Works in pH 2–12, compatible with acidic/alkaline formulations. |
| Low Toxicity | Skin-friendly (used in personal care) and biodegradable (~70–80%). |
| Synergy | Boosts performance when combined with polycarboxylates (e.g., PCA). |
6. Comparison with Alternatives
| Agent | PBTC | EDTA | Citric Acid |
|---|---|---|---|
| Chelation Strength | Strong (Log K Ca²⁺ ~6.5) | Very Strong (Log K ~10) | Weak (Log K ~3.5) |
| Biodegradability | Moderate (~70%) | Poor (<10%) | Excellent (100%) |
| Cost | Moderate | High | Low |
| Phosphorus Content | Yes (regulatory limits apply) | No | No |
7. Regulatory & Safety Notes
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Phosphorus Regulations: PBTC contains phosphorus; check local limits (e.g., EU Detergent Regulation EC 648/2004).
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Eco-Labels: Approved for use in EU Ecolabel and Blue Angel certified products (within specified limits).
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Skin Safety: Non-irritating at recommended doses (tested per OECD 439).
Conclusion
PBTC is a versatile, efficient, and stable ingredient in daily chemicals, particularly for:
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Hard water scale prevention (laundry, dishwashing).
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Performance enhancement (lathering, cleaning).
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Product stability (metal ion sequestration).
For formulations, optimize dosage based on water hardness and combine with polycarboxylates (e.g., PCA) for cost-effective scale control. Always comply with regional phosphorus regulations.