CP-388 is a premium organophilic clay selected for high-purity applications requiring low residual silica content, fine dispersion fineness, and transparent gel quality. It covers the widest solvent polarity range of any standard CP organoclay grade — from non-polar mineral oils to highly polar ketone and ester systems. CP-388 is the preferred grade for top-grade decorative coatings where visual clarity and color are critical, high-quality printing inks requiring fine dispersion, and polymer nano-composite applications where platelet purity affects composite mechanical properties.
Technical Properties
| Parameter | Specification | Test Method |
|---|
| Chemical composition | Organic derivative of montmorillonite clay (high purity) | — |
| Appearance | Fine powder, light yellow | Visual |
| Moisture content | ≤ 3.5% | 105°C, 2 hours |
| Loss on ignition (LOI) | 31–34% | 1000°C |
| Fineness | ≥ 98% passing 74 μm (200 mesh) | Sieve analysis |
| Purity | High purity — low residual silica content | XRF |
| Gel appearance | Very transparent, light color | Visual |
Performance Characteristics
- High purity, low silica content — selected from premium bentonite with minimal quartz and accessory mineral contamination; ensures gel clarity and reduces abrasion in ink and cosmetic applications
- Fine dispersion and particle size — achieves complete exfoliation at lower mixing energy; fewer undispersed aggregates in the final product
- Wide application range — effective across the full polarity spectrum from non-polar to highly polar organic systems
- High viscosity and thixotropy efficiency — achieves target TI at lower dosage than standard-purity organoclay grades due to more complete platelet exfoliation
- Very transparent, light-colored gel — critical for clear coatings, transparent inks, and cosmetics where product appearance matters
Applications and Dosage
| Application | Typical Dosage | Key Reason for CP-388 |
|---|
| Top-grade decorative paint | 0.2–0.8 wt% | Transparency, color neutrality in light tints |
| Industrial paint (high spec) | 0.3–1.0 wt% | Wide polarity range, consistent performance |
| High-quality printing ink | 0.5–2.0 wt% | Low silica — no abrasion on printing plates/cylinders |
| Lubricating grease | 8–15 wt% | Purity for demanding specialty grease applications |
| Cosmetics (anhydrous) | 1.0–5.0 wt% | High purity, transparent gel, low skin abrasion |
| PE / PP nano-composites | 1.0–10 wt% | Pure clay platelets — better exfoliation in polymer melt |
When to Specify CP-388: Choose CP-388 when purity, gel transparency, and wide polarity compatibility are all required simultaneously. For standard-specification industrial coatings where transparency is not critical, CP-34 or CP-APA offers equivalent rheology at lower cost. CP-388 is the premium choice for top-grade, specification-sensitive, or multi-market formulations.
Incorporation Method
- Direct powder addition under high shear at 0.1–1.0% of total formulation weight
- Add before grinding for best effectiveness in paint and ink applications
- Polar activator optional but improves performance in low-polarity systems: 30–40% ethanol by CP-388 weight
- High-shear dispersion at 1,500–3,000 rpm for 10–15 minutes
- For polymer compounding: add as dry powder at hopper or pre-mix with carrier resin before extruder
Frequently Asked Questions
What makes CP-388 a high-purity organoclay?
CP-388 is produced from selected high-purity bentonite with lower residual quartz (free silica) and accessory mineral content than standard organoclay grades. Lower silica improves gel clarity, reduces abrasion in printing ink and cosmetic applications, and provides cleaner rheological performance. Higher ore purity also gives better batch-to-batch consistency in performance-sensitive formulations.
What solvent polarity range does CP-388 cover?
CP-388 covers the widest polarity range of standard CP organoclay grades — from non-polar mineral oils and aliphatics to highly polar ketones, esters, and ether esters. This broad compatibility suits multi-solvent formulations and variable-polarity systems. Polar activator (30–40% ethanol) improves performance in low-polarity systems; direct addition works in moderate to high-polarity solvents.
Is CP-388 suitable for use in PE and PP composites?
Yes. CP-388 is used in PE/PP nano-composites as a clay reinforcing agent. During melt compounding, high-purity organoclay platelets intercalate and exfoliate in the polymer matrix, improving tensile strength, flexural modulus, and barrier performance. The fine particle size and purity of CP-388 promote better exfoliation in polyolefin melt processing than standard-purity grades.
Packaging and Storage
| Parameter | Specification |
|---|
| Standard packaging | 25 kg kraft paper bags with PE inner liner |
| Shelf life | 2 years from manufacture date |
| Storage conditions | Cool, dry, well-ventilated warehouse; avoid moisture exposure |
Related grades: CP-34 (general purpose) ·
CP-APA (self-activating) ·
CP-180B (transparent coatings)
Related applications: Paint & Coatings ·
Printing Ink ·
Cosmetics ·
Lubricating Grease
