Calcium Stearate, Calcium Distearate, Calcium Soap, 1592-23-0

Calcium Stearate, Calcium Distearate, Calcium Soap, 1592-23-0

CALCIUM STEARATE

Calcium Stearate / Calcium Distearate / Calcium Soap / Octadecanoic Acid Calcium Salt
CAS Number: 1592-23-0
EC Number: 216-472-8

1. PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY

Calcium stearate is the calcium salt of stearic acid (octadecanoic acid). It is a white, silky fine powder classified as a metal salt (fatty acid salt) and is commonly known as "calcium soap." Calcium stearate is produced by the reaction of stearic acid with lime (calcium oxide or calcium hydroxide). It is insoluble in water but soluble in hot organic solvents (alcohol, benzene, toluene, xylene, acetone). Due to its high thermal stability, excellent water resistance, and non-toxicity, it can even be used as a food additive. Calcium stearate is widely used in the plastics and rubber industry as a stabilizer, lubricant, and release agent; in cosmetic products as an emulsifier and stabilizer; in the pharmaceutical industry as a binder and lubricant in tablet production; in paints and coatings as a flatting and sanding agent; and in construction materials as a water-repellent agent.

2. PHYSICAL AND CHEMICAL PROPERTIES

Calcium stearate is a white, fine powder with a silky feel when touched. Its true density is approximately 1.03-1.08 g/cm³, while its bulk density ranges from 0.2-0.5 g/cm³ depending on the form. The melting point is approximately 180°C, at which decomposition begins. It is practically insoluble in water but soluble in hot alcohol, benzene, toluene, xylene, and acetone. The pH of its aqueous suspension is approximately 9-10, indicating basic character. It is highly hydrophobic (water-repellent). Free fatty acid content is ≤ 0.5%, loss on drying is ≤ 2.0%, and residue on ignition is approximately 8-12%. Calcium oxide (CaO) content is approximately 9-11%. Heavy metals are typically ≤ 20 ppm (as Pb). It is stable under normal conditions and highly stable at elevated temperatures. It is incompatible with strong acids and strong oxidizing agents. It is non-toxic and can even be used as a food additive.

3. CHEMICAL PROPERTIES AND REACTIONS

Calcium stearate is a calcium metal salt and a fatty acid soap (calcium soap). Its chemical behavior is determined by the properties of the stearate anion and the calcium cation.

Reaction with Acids:

Calcium stearate reacts with strong acids to form stearic acid and the corresponding calcium salt:

(C₁₇H₃₅COO)₂Ca + 2 HCl → 2 C₁₇H₃₅COOH + CaCl₂

Production Reaction (Stearic Acid + Calcium Oxide):

Calcium stearate is produced by the reaction of stearic acid with calcium oxide (lime) or calcium hydroxide:

2 C₁₇H₃₅COOH + CaO → (C₁₇H₃₅COO)₂Ca + H₂O

Hydrolysis:

Although insoluble in water, calcium stearate can hydrolyze at high temperatures or under extremely acidic or basic conditions.

Thermal Decomposition:

At temperatures above 180°C, calcium stearate decomposes to form calcium carbonate, carbon dioxide, and hydrocarbons.

Saponification:

As a soap (fatty acid salt), calcium stearate exhibits surfactant properties and can stabilize emulsions.

Combustion:

Calcium stearate is combustible and upon burning produces calcium oxide, carbon dioxide, and water.

Hard Water Tolerance:

Unlike sodium stearate and potassium stearate, calcium stearate does not have precipitation problems with hard water because it is already present as insoluble calcium stearate. This makes it advantageous in some specialized applications.

4. PRODUCTION METHODS

Calcium stearate is produced industrially by the reaction of stearic acid with calcium oxide (lime) or calcium hydroxide.

Detailed Production Process (Direct Reaction - Most Common):

1. Raw Material Preparation: Stearic acid and calcium oxide (lime) or calcium hydroxide are prepared. Stearic acid is typically melted.

2. Reaction: Molten stearic acid is reacted with calcium oxide or calcium hydroxide. The reaction is typically carried out at 80-150°C with stirring:

2 C₁₇H₃₅COOH + CaO → (C₁₇H₃₅COO)₂Ca + H₂O

2 C₁₇H₃₅COOH + Ca(OH)₂ → (C₁₇H₃₅COO)₂Ca + 2 H₂O

3. Water Removal: The water formed during the reaction is removed by vacuum or inert gas flow.

4. Cooling and Solidification: The reaction mixture is cooled to solidify the calcium stearate.

5. Milling and Sieving: The solid calcium stearate is milled to the desired particle size and sieved.

6. Packaging: The final product is packaged in 25 kg bags, drums, or FIBCs.

Reaction Equation (with Calcium Oxide):

2 C₁₇H₃₅COOH + CaO → (C₁₇H₃₅COO)₂Ca + H₂O

5. COMPARISON WITH OTHER METAL STEARATES

Calcium stearate is known for its high thermal stability and excellent water resistance. It is widely used as a PVC stabilizer. Magnesium stearate is the most widely used metal stearate in pharmaceutical applications. Zinc stearate is common in cosmetic and paint applications. Lithium stearate is used in high-temperature lubricating greases.

6. APPLICATIONS AND INDUSTRIAL USES

Calcium stearate has a wide range of applications across various industries due to its excellent thermal stability, water resistance, lubricating properties, and non-toxicity.

6.1. Plastics and Polymer Industry (Most Important Application)

Calcium stearate is one of the most widely used additives in the plastics and polymer industry. It plays a critical role as a stabilizer, lubricant, and release agent in the processing of PVC and other polymers. It increases the durability of plastics against external factors such as heat and light. During processing, it improves the processability of materials by increasing fluidity; it improves product homogeneity, reduces energy consumption, and saves raw materials. It enables better transparency, good color retention, long-term stability, and weather resistance.

6.2. Food Industry

Calcium stearate is used as a food additive (E 470) as an emulsifier, stabilizer, anti-caking agent, and lubricant. It ensures the mixing of oil and water phases in food products, improving product homogeneity. It is non-toxic and considered safe as a food additive.

6.3. Cosmetics and Personal Care Products

Calcium stearate is used in cosmetic and personal care products as an emulsifier, stabilizer, anti-caking agent, and lubricity enhancer. It is found in creams, lotions, powders, deodorants, and makeup products.

6.4. Pharmaceutical Industry

Calcium stearate is used in the pharmaceutical industry as a lubricant and binder in tablet production, as well as an excipient and emulsion stabilizer. However, it is not as common as magnesium stearate.

6.5. Paints and Coatings

Calcium stearate is used in the paint and coating industry as a flatting agent, sanding agent, suspension agent, and water repellent.

6.6. Construction and Building Materials

Calcium stearate is used as an additive in construction materials to improve water resistance and durability. It acts as a water-repellent agent in joints, plasters, and waterproofing products.

6.7. Rubber Industry

Calcium stearate is used in the rubber industry as a release agent, lubricant, anti-blocking agent, and accelerator activator.

6.8. Textile Industry

Calcium stearate is used in the textile industry as a softener, lubricant, and water repellent.

6.9. Other Applications

7. SAFETY AND HEALTH INFORMATION

Calcium stearate is non-toxic and can even be used as a food additive. It has very low toxicity.

7.1. Toxicological Data

7.2. Health Effects

8. FIRST AID MEASURES

9. SAFETY INFORMATION (GHS CLASSIFICATION)

Calcium stearate is not classified as a hazardous substance under GHS.

Signal Word: WARNING

Hazard Statements (H-Codes):

Precautionary Statements (P-Codes):

10. FIREFIGHTING MEASURES

11. ACCIDENTAL RELEASE MEASURES

12. STORAGE AND HANDLING

Calcium stearate should be stored in cool, dry, well-ventilated areas in tightly closed original containers. It should be kept away from heat, moisture, and ignition sources. Contact with strong acids and strong oxidizing agents should be avoided. Proper grounding should be used to prevent static electricity accumulation.

Handling Notes:

• Avoid dust generation (use enclosed systems, local exhaust ventilation)

• Avoid contact with skin and eyes (use protective gloves and goggles)

• Avoid breathing dust (use dust mask or respirator)

• Keep away from ignition sources

13. TRANSPORT INFORMATION

Calcium stearate is not classified as a dangerous good for transport. It is shipped in 25 kg bags, drums, or FIBCs. During transport, protect from moisture, impact, and excessive heat.

14. REGULATORY INFORMATION

Regulatory Status:

15. OTHER NAMES AND DATABASE IDENTIFIERS

Database Identifiers:

16. ENVIRONMENTAL INFORMATION

17. APPLICATION SUMMARY TABLE

18. PHYSICAL FORMS

19. COMPARISON WITH OTHER CALCIUM SOAPS

Calcium stearate is the most commonly used calcium soap. Calcium palmitate and calcium oleate are also used but are not as common as calcium stearate.

20. SUMMARY AND CRITICAL WARNINGS

SUMMARY:

Calcium stearate (C₃₆H₇₀CaO₄, CAS 1592-23-0) is the calcium salt of stearic acid (octadecanoic acid). It is a white, silky fine powder classified as a metal salt (fatty acid salt) and is commonly known as "calcium soap." The molecular weight is 607.02 g/mol, and the melting point is approximately 180°C. It is practically insoluble in water but soluble in hot alcohol, benzene, toluene, xylene, and acetone. It is produced by the reaction of stearic acid with lime (calcium oxide or calcium hydroxide). It is non-toxic and can even be used as a food additive. Its most important applications include: PVC stabilizer, lubricant, and release agent in the plastics and polymer industry; emulsifier and stabilizer (E 470) in the food industry; emulsifier and stabilizer in cosmetic products; tablet lubricant and binder in the pharmaceutical industry; water-repellent agent in construction materials; and flatting and sanding agent in paints and coatings. It has very low toxicity and is not classified as a hazardous substance under GHS. It is stored in cool, dry, well-ventilated areas, protected from heat and moisture. Packaging: 25 kg bags, drums, or FIBCs.

Key Properties:

Major Application Areas:

Key Safety Points:

• VERY LOW TOXICITY: GRAS by FDA; approved as food additive

• COMBUSTIBLE DUST: Avoid dust cloud formation; use explosion-proof equipment

• MILD IRRITANT: May cause mild skin and eye irritation

• WATER INSOLUBLE: Insoluble in water; soluble in organic solvents

• STORAGE: Store in cool, dry, well-ventilated area, away from heat and moisture

• USE PPE: Dust mask, gloves, safety goggles (if dust formation occurs)

CRITICAL WARNINGS:

PVC Stabilizer: Calcium stearate is one of the most widely used heat stabilizers for PVC and other polymers. It increases the durability of plastics against external factors such as heat and light. During PVC processing, calcium stearate prevents polymer degradation by inhibiting the release of hydrogen chloride (HCl).

Lubricant and Release Agent: Calcium stearate is an excellent lubricant and release agent during plastic and rubber processing. It improves the processability of materials by increasing fluidity; it improves product homogeneity, reduces energy consumption, and saves raw materials.

Food Additive: Calcium stearate is used as a food additive (E 470) as an emulsifier, stabilizer, and anti-caking agent. It is non-toxic and Generally Recognized as Safe (GRAS) by the FDA.

Water-Repellent Properties: Calcium stearate is highly hydrophobic (water-repellent). Therefore, it is used to provide water resistance in construction materials, impart water repellency in coatings, and provide water-repellent properties in cosmetic products.

Thermal Stability: Calcium stearate is highly stable at elevated temperatures. This property makes it an ideal additive for plastics and other materials processed at high temperatures.

Dust Explosion: Calcium stearate dust can reach explosive concentrations in air. Explosion-proof equipment, proper grounding, and dust collection systems should be used to prevent explosion risk. Static electricity accumulation should be avoided.

Environment: Calcium stearate is readily biodegradable due to its fatty acid component. It has low toxicity to aquatic organisms. Large discharges to water bodies should be avoided.

Important Disclaimer: This Technical Data Sheet (TDS) is for informational purposes only. The information provided is based on available data and is believed to be accurate. However, the user is solely responsible for determining the suitability of the product for their specific application and for complying with all applicable regulations and safety requirements. For complete safety, handling, storage, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. Users are responsible for testing the product in their own processes and applications. All local, national, and international regulations must be followed when working with calcium stearate.