Hydrogenated Castor Oil (HCO) Flakes: Technical Specifications and Industrial Utility

1. Technical Overview

Hydrogenated Castor Oil (HCO), also known as castor wax, is a hard, brittle, high-melting-point vegetable wax produced through the controlled hydrogenation of First Special Grade Castor Oil.² Chemically, it is the triglyceride of 12-hydroxystearic acid. During the process, the double bonds in the ricinoleic acid chain are saturated with hydrogen, transforming the liquid oil into a solid crystalline wax. In industrial R&D, HCO is valued for its unique ability to provide thixotropic properties and water resistance in non-polar systems, making it a critical ingredient for high-performance lubricant greases and specialized coatings.

2. Chemical Structure & Composition

The molecular profile of HCO Flakes is defined by the conversion of Ricinoleic acid into 12-Hydroxystearic acid (12-HSA).

• Tri-12-Hydroxystearin: The primary component (~85–90%).

• Saturated Fatty Acids: Increased concentration of stearic acid components due to hydrogenation.

• Hydroxyl Functionality: Unlike petroleum-based waxes, HCO retains its hydroxyl groups, which allows for secondary chemical reactions such as esterification or the formation of metallic soaps.³

3. Physical & Chemical Properties

HCO Flakes are characterized by their physical hardness and thermal stability.⁴

• Melting Point: Typically 85°C to 88°C, significantly higher than most natural waxes.⁵

• Appearance: Hard, white to off-white flakes.⁶

• Solubility: Insoluble in water and most common organic solvents at room temperature.⁷ It becomes soluble in various organic liquids (like mineral oils or toluene) when heated above its melting point but forms a gel upon cooling.

• Odor: Neutral to very faint fatty odor.

4. Reaction Chemistry

In the reactor, HCO behaves as a multifunctional lipid.

1. Saponification: Reacts with lithium or calcium hydroxides to form high-temperature stable greases.

2. Thixotropy: When dispersed in a solvent and cooled under shear, it forms a network of microscopic fibers that provide sag resistance in paints and sealants.⁸

3. Esterification: The hydroxyl group remains available for reaction with organic acids to produce specialized esters.

5. When to Use vs. When NOT to Use

Use HCO Flakes when:

• You require a bio-based rheology modifier for solvent-borne coatings.

• Formulating high-drop-point lithium greases.⁹

• Manufacturing paper coatings or textile finishes that require high water repellency.

Do NOT use HCO Flakes when:

• The formulation is strictly water-based without specialized emulsifiers (as HCO is highly hydrophobic).

• The application cannot tolerate a crystalline structure or requires a clear, transparent liquid at room temperature.

6. Compatibility Profile

HCO is compatible with most natural and synthetic waxes, including Carnauba, Paraffin, and Beeswax.¹⁰ It shows excellent synergy with:

• Resins: Alkyds, epoxies, and polyurethanes.¹¹

• Solvents: Aliphatic and aromatic hydrocarbons (at elevated temperatures).

• Polymers: Polyethylene and polypropylene as a processing aid.¹²

7. Manufacturing Process (Product Focus)

The production of high-grade HCO Flakes involves:

1. Feedstock Selection: Using FSG Castor Oil with low acid value to prevent catalyst poisoning.

2. Catalytic Hydrogenation: Subjecting the oil to hydrogen gas at high pressure and temperature in the presence of a nickel catalyst.¹³

3. Filtration: Removing the catalyst residue to ensure ultra-low nickel content.

4. Flaking: The molten wax is passed over a chilling roller to form consistent, easy-to-handle flakes.

8. Technical Specifications Table

Parameter	Specification (HCO Flakes)
Appearance	White to Off-White Flakes
Melting Point (°C)	85 – 88°C
Acid Value (mg KOH/g)	3.0 Max
Iodine Value (g I2/100g)	5.0 Max
Saponification Value	175 – 185
Hydroxyl Value	150 – 165
Color (Gardner)	3.0 Max
Nickel Content	< 5 ppm

9. Quality Grade Analysis

Nova Industries ensures that the Iodine Value is strictly controlled below 5.0. A higher iodine value indicates incomplete hydrogenation, which results in a lower melting point and reduced oxidative stability—a common defect in lower-tier industrial waxes that leads to “softening” of the final grease or coating.

10. Impact of Impurities

• Residual Nickel: Excess catalyst can cause discoloration in cosmetic applications and interfere with the electrical properties of cable compounds.

• High Acid Value: Indicates potential hydrolysis, which can affect the stoichiometry in soap-making (grease) processes.

11. Industry-Wise Application 1: Lubricants & Greases

HCO is the cornerstone of the “Lithium-Base Grease” industry. When reacted with Lithium Hydroxide, it forms Lithium 12-Hydroxystearate. This soap provides the fibrous structure necessary to hold base oils in place, offering superior mechanical stability and water wash-out resistance in automotive and industrial bearings.

12. Industry-Wise Application 2: Coatings & Sealants

In the paint industry, HCO acts as a thixotropic agent.¹⁴ It prevents the pigment from settling during storage and prevents sagging when the paint is applied to vertical surfaces. It is widely used in marine paints and heavy-duty industrial coatings.

13. Industry-Wise Application 3: Plastics & Polymers

HCO Flakes serve as an external lubricant and release agent for PVC and other plastics.¹⁵ It improves the flow of the melt and prevents the polymer from sticking to the metallic parts of the extruder or mold.¹⁶

14. Industry-Wise Application 4: Cosmetics & Pharma

In stick-form cosmetics (lipsticks, deodorants), HCO provides structural integrity and temperature stability.¹⁷ It prevents the product from melting in warm climates while providing a smooth, non-greasy application.

15. Formulation Guide

• Activation: To act as a thickener, HCO must be “activated” by heating it in the solvent to its specific activation temperature (usually 5°C below its melting point) followed by controlled cooling under agitation.

• Dispersion: For plastics, HCO flakes can be dry-blended with resin pellets before extrusion.

16. Sustainability Data

Hydrogenated Castor Oil is a 100% renewable, bio-based material. It is a sustainable alternative to petroleum-derived microcrystalline waxes.¹⁸ It is inherently biodegradable and poses minimal environmental risk.

17. Packaging & Logistics (Technical)

• Packaging: 25kg Paper Bags with inner PE liner to prevent moisture absorption.

• Palletization: Standard 1-ton pallets, shrink-wrapped to ensure stability during export transit.¹⁹

• Logistics: Due to its high melting point, HCO is stable for transport in standard containers without climate control.

18. Storage Science

HCO should be stored in a cool, dry place. Although it has a high melting point, exposure to temperatures above 45°C for prolonged periods can lead to “caking” or clumping of the flakes, making them difficult to dispense in automated weighing systems.

19. Troubleshooting Guide

• Problem: Particle “seeds” in coatings. Solution: Ensure the HCO was fully melted and then cooled at the correct rate; “seeding” usually occurs due to improper activation temperature.

• Problem: Low grease consistency. Solution: Check the Hydroxyl Value of the HCO; a low HV indicates fewer sites for soap formation.

20. Regulatory Compliance

Our HCO Flakes are REACH Compliant and meet the requirements for various international chemical inventories.²⁰ It is recognized as safe for use in indirect food contact applications (packaging).

21. Safety (SDS Summary)

• Handling: Use dust masks when handling flakes to avoid inhalation of fine particles.

• Flammability: HCO has a high flash point (>200°C) and is not classified as flammable under GHS.

• First Aid: Wash skin with soap and water. Flush eyes with water if contact occurs.

22. Sample Validation Process

For laboratory validation, we recommend focusing on the Melting Point and Iodine Value. These parameters confirm the degree of hydrogenation and ensure the wax will perform correctly in high-heat applications.

23. Commercial Efficiency

Using high-purity HCO Flakes reduces the volume of rheology modifiers needed in a formulation. The consistent flake size allows for faster melting and shorter batch cycle times in manufacturing.

24. Technical FAQs

1. Can HCO be used in water-based paints? It requires pre-emulsification or the use of specialized surfactants to be effective in aqueous systems.

2. What is the difference between HCO and 12-HSA? HCO is the triglyceride (the wax), while 12-HSA is the fatty acid derived from it. HCO is preferred when the glycerin backbone is beneficial to the formulation.

3. Does HCO affect the color of the final product? Nova Industries’ HCO is highly bleached to ensure minimal impact on the color of white or clear coatings.

25. Contact CTA

For technical data sheets, bulk pricing, or custom specifications, please contact our export department: export@novaind.in