Industry Grade 99% Calcium Stearate CAS 1592-23-0

What is calcium stearate? How does it work? What are all its uses?

What is Calcium stearate? How does it work?

Calcium stearate, also known as calcium stearate (or calcium stearate salt), has the chemical formula Ca(C18H35O2)2, a molecular weight of 607.03, CAS number 1592-23-0, ECHA number 100.014.976, UNII 776XM7047L, and DTXSID7027419. It is a fatty acid calcium salt composed of one calcium ion and two stearate groups (octadecanoate group). It belongs to the metal soap (calcium soap) family and is systematically recorded in the "Metal Soaps" entry of the Ullmann Encyclopedia of Industrial Chemistry. It is a white to slightly yellow powder and one of the most widely produced and used metallic soaps in industry. As a PVC heat stabilizer (the core calcium component of the calcium-zinc stabilization system) and a plastic lubricant and release agent, calcium stearate is present in almost all soft and hard PVC products. It is also a thickener for lubricating greases, a softener for rubber, a waterproofing agent for concrete, a lubricant for papermaking, a waterproofing agent for fabrics, a matting agent for coatings, a powder additive in cosmetics, and a component of defoamers. It is known as the "white lubricant of the plastics and building materials industry." Note: Calcium stearate is non-toxic, inexpensive, and readily available.

Basic information : Chemical formula Ca(C18H35O2)2, molecular weight 607.03; CAS number 1592-23-0; ECHA number 100.014.976; UNII 776XM7047L; EPA DSSTox DTXSID7027419; ChEBI 190296; ChemSpider 14587; Food additive number E470a (food grade); Aliases: calcium stearate, calcium octadecanoate, calcium stearate salt, calcium octadecanoate, calcium distearate.

Structurally and in manufacturing, calcium stearate is a typical metal soap, consisting of calcium ions bonded to two stearate groups via ionic bonds. Industrially, it is manufactured via two routes: the direct method—stearic acid reacts with calcium oxide (or calcium hydroxide) at 140-150℃ to dehydrate (2C17H35COOH + CaO → Ca(C18H35O2)2 + H2O); and the metathesis method—sodium stearate solution reacts with calcium chloride solution at approximately 65℃ to precipitate the product, followed by washing, drying, and pulverizing. Commercially available forms include powder and a 50% aqueous dispersion.

Physically , calcium stearate is a white to slightly yellow fine powder, odorless or with a slightly fatty odor; density approximately 1.04-1.08 g/cm³; softening point approximately 150℃; melting range approximately 147-180℃ (data varies from source to source, CRC records 180℃, Baidu Encyclopedia records 147-149℃); boiling point approximately 359℃ (760 mmHg); flash point approximately 162℃; almost insoluble in water (approximately 0.004 g/100 mL @15℃), cold ethanol and benzene, slightly soluble in hot oil, soluble in hot pyridine and hot toluene; oleophilic and hydrophobic, with a low coefficient of friction (lubricating) and anti-caking properties.

Chemically , calcium stearate is a chemically stable calcium soap: it has good thermal stability (high decomposition temperature); it reacts with inorganic acids to release stearic acid; it reacts with hydrogen chloride (HCl) released from PVC degradation to produce calcium chloride and stearic acid (acid scavenging effect, which is the basis of PVC's thermal stability); it can undergo metal exchange with zinc soap (calcium and zinc synergistic stabilization); it is non-toxic and has almost no effect on rubber vulcanization; its slightly soluble in oil and insoluble in water properties determine its lubricating, waterproofing, and anti-caking functions.

From the perspective of its mechanism of action, calcium stearate plays an irreplaceable role due to its six properties: long-chain lubrication, acid scavenging, hydrophobic film formation, calcium-zinc synergy, fiber thickening, and powder anti-caking.

Long-chain lubrication mechanism : Two C17 long-chain fatty acid roots form a layered structure with low interlayer shear force. In plastic processing (extrusion, injection molding, calendering) and metal processing, it plays a role in internal and external lubrication, reducing friction and melt sticking to the wall, and promoting demolding. This is the functional basis for its use as a plastic lubricant, mold release agent and cosmetic slip agent.

Acid removal mechanism (PVC thermal stability) : PVC processing degrades upon heating, releasing hydrogen chloride. Calcium stearate reacts with this hydrogen chloride to form calcium chloride and stearic acid, neutralizing the acidity and inhibiting the chain degradation of PVC (autocatalytic deHCl removal). As an acid scavenger, its dosage can reach up to 1000 ppm, extending the PVC processing window and product lifespan.

Calcium-zinc synergistic mechanism (lead-free stabilizing system) : In calcium-zinc composite stabilizers, calcium stearate and zinc stearate are used together: zinc soap has high initial stabilizing activity but will generate ZnCl2 for catalytic degradation ("zinc burning"). Calcium soap and ZnCl2 undergo metal exchange to regenerate zinc soap and passivate ZnCl2, achieving long-term synergistic stabilization. This is the core of a non-toxic stabilizing system that replaces lead salts.

Hydrophobic film-forming mechanism (waterproofing and anti-caking) : Calcium stearate, with its lipophilic fatty acid long chains facing outwards and calcium ions facing inwards, forms a hydrophobic film at the water/solid interface, preventing water molecules from penetrating. It is used for waterproofing concrete blocks, waterproofing fabric finishing, and controlling salt seepage (alkali bloom). Its hydrophobic fine powder coating forms an isolation layer on the surface of powder particles, preventing the formation of liquid bridges and crystal bridges between particles. This is the mechanism basis for its use as an anti-caking agent in cosmetics, feed and fertilizer powders, and a candy dispersant.

Fiber thickening mechanism (grease) : Calcium stearate is saponified in base oil to form a fibrous network structure. The interwoven fibers encapsulate the base oil to form a semi-solid grease, which is a thickener for calcium-based greases (cup greases).

In summary , calcium stearate is a versatile metallic soap used in a wide range of applications, from PVC pipes and concrete blocks to greases and waterproof canvases, and from loose powder and lipstick to salt and milk powder. With long-chain lubrication and acid removal as its core properties, it spans fields such as plastics, rubber, greases, building materials, papermaking, textiles, coatings, metal processing, defoaming, cosmetics, food, feed, and agriculture. It is one of the most produced and widely used varieties in the metallic soap family.

What are all the uses of Calcium stearate?

1. PVC heat stabilizer (core application in the plastics industry)

Application areas: PVC processing and products.

Corresponding products: Stabilizers for rigid PVC pipes and profiles, calcium-zinc composite heat stabilizers, PVC cable material stabilizers, non-toxic PVC film stabilizers (food packaging), PVC sheet and board stabilizers, PVC foam product stabilizers, environmentally friendly lead-free stabilization systems, etc.

Why it can be used in this way: Calcium stearate acts as an acid scavenger, absorbing hydrogen chloride released during the degradation of PVC during processing and inhibiting chain degradation (as a PVC heat stabilizer, it can increase the gelation rate when combined with basic lead salts and lead soaps in rigid products); in calcium-zinc composite stabilizers, it works synergistically with zinc stearate (metal exchange passivation of ZnCl2 prevents "zinc burning"), and is the core calcium component of environmentally friendly lead-free PVC stabilization systems, as well as a standard stabilizer for non-toxic flexible films such as food packaging.

2. Plastic processing lubricants, mold release agents, and acid removers (plastic processing field)

Application areas: Plastic molding and processing.

Corresponding products: PVC processing internal lubricant, plastic release agent, rigid PVC gel accelerator, polyethylene and polypropylene halogen absorbent (residual catalyst removal), masterbatch pigment wetting agent, phenolic and amino thermosetting plastic release agent, injection molding lubricant, extrusion molding aid, etc.

Why it can be used in this way: The long-chain structure of calcium stearate acts as an internal and external lubricant in plastic processing, reducing melt sticking to the wall and friction, promoting demolding, accelerating gelation in rigid PVC, improving flow and reducing die swell (clearly recorded in Wikipedia); as an acid scavenger, it can absorb the adverse effects of residual catalysts (halogens) in polyethylene and polypropylene on color and stability, making it a multifunctional additive in plastic processing.

3. Rubber processing softeners (rubber industry)

Application area: Rubber processing.

Corresponding products: natural rubber softener, synthetic rubber plasticizer, tire compound processing aid, rubber seal softener, rubber hose and tape softener, rubber shoe sole additive, rubber compound lubricant, etc.

Why it can be used in this way: Calcium stearate has good compatibility with rubber. As a softener, it reduces the viscosity of rubber compounds, improves processing fluidity and product softness, and has almost no effect on rubber vulcanization (Baidu Encyclopedia clearly states that it can soften natural and synthetic rubbers while having almost no effect on vulcanization). It is a safe processing aid for rubber formulations.

4. Grease thickeners (grease industry)

Application area: Lubricating grease manufacturing.

Corresponding products: calcium-based grease (cup grease), general industrial grease, agricultural machinery grease, bearing grease, wheel hub grease, wire rope grease, rust-preventive grease, etc.

Why it can be used for this purpose: Calcium stearate saponifies in base oil to form a fibrous three-dimensional network structure. The interwoven fibers encapsulate the base oil and bind it into a semi-solid state, giving the grease consistency, thixotropy and high-temperature stability (Wikipedia records it as a component of grease, and Baidu Encyclopedia clearly records it as a grease thickener). It is the standard thickener for calcium-based greases (cup greases).

5. Concrete waterproofing agents and salt control agents (building materials industry)

Application areas: Concrete and cement products.

Corresponding products: waterproofing agent for concrete blocks, waterproofing agent for paving bricks (Paver), cement-based waterproofing materials, concrete salt bleeding (efflorescence) control agent, waterproof mortar, waterproofing agent for precast concrete components, roof waterproofing boards, etc.

Why it works for this purpose: The hydrophobic fatty acid long chains of calcium stearate form a hydrophobic film on the cement pore walls, reducing the water absorption rate of concrete and improving its impermeability and waterproofing performance. At the same time, it inhibits the migration of soluble salts with water to the surface to form efflorescence, which is used for waterproofing and salt control of concrete blocks and paving bricks (clearly recorded by Wikipedia and the Portland Cement Association of the United States).

6. Paper coating lubricant (paper industry)

Application areas: Paper and paperboard industry.

Corresponding products: coated paper lubricant, coated paper coating aid, paperboard gloss agent, anti-powdering coating agent, anti-cracking lubricant, paper surface coating defoaming component, specialty paper processing aid, etc.

Why it serves this purpose: Calcium stearate acts as a lubricant in paper coating formulations, providing good gloss, preventing dusting on the coated surface, and preventing paperboard from cracking during folding (as clearly stated in Wikipedia). It is an important additive in the production of coated paper and paperboard.

7. Fabric waterproofing agents (textile industry)

Application area: Textile finishing.

Corresponding products: waterproof canvas finishing agent, tent fabric waterproofing agent, rain tarpaulin waterproofing finishing agent, coated fabric waterproofing additive, workwear waterproofing finishing agent, outdoor fabric water repellent agent, etc.

Why it works for this purpose: The hydrophobic long chains of calcium stearate are oriented to form a hydrophobic film on the surface of fabric fibers, reducing the surface energy of the fabric and preventing water from wetting and penetrating. It is a fabric waterproofing agent clearly recorded by Wikipedia and is used for waterproofing finishing of canvas and outdoor fabrics.

8. Coating matting agents and pigment dispersing aids (coating industry)

Application areas: Coatings and inks industry.

Corresponding products: paint matting agent (matting agent), latex paint matting additive, pigment dispersant, anti-settling agent, powder coating additive, printing ink anti-settling additive, sand texture coating additive, wood coating matting powder, etc.

Why it can be used for this purpose: Calcium stearate is used in coatings as a matting agent to reduce the gloss of the paint film (Baidu Encyclopedia clearly states that it is used as a matting agent for paint). Its fine powder can also improve pigment wetting and prevent sedimentation, and regulate the rheology of coatings. It is a multifunctional powder additive for coating formulation.

9. Metal drawing lubricants and pencil/crayon lubricants (metal processing and stationery manufacturing fields)

Application areas: Metal wire processing and stationery manufacturing.

Corresponding products: dry drawing lubricant for copper and aluminum wires, drawing lubricant powder for steel wires, pencil lead lubricant, crayon lubricant, metal forming lubricant, cold heading lubricant, welding wire lubricant, etc.

Why it can be used for this purpose: The low-shear layered structure of calcium stearate forms a lubricating film on the metal surface, which is the standard lubricant for dry drawing processes (clearly stated in Wikipedia), reducing drawing friction and energy consumption; its lubricity is also used in the manufacture of pencil leads and crayons (recorded as a pencil lead lubricant in Baidu Encyclopedia).

10. Industrial defoamer components (fermentation and chemical industries)

Application areas: fermentation, papermaking and chemical defoaming.

Corresponding products: fermentation defoamer components, papermaking defoamer, coating defoamer, wastewater treatment defoamer, chemical reaction defoamer, water-based system defoamer, etc.

Why it works for this purpose: Calcium stearate is a component of some defoamer formulations (Wikipedia clearly states that it is an ingredient in some defoamers). Its hydrophobic particles can insert into the foam liquid film and disrupt the stability of the film to break the foam, and it is used for foam control in fermentation, papermaking and chemical systems.

11. Anti-caking agents and lubricants for cosmetic powders (cosmetic industry)

Application areas: Powder cosmetics and personal care.

Corresponding products: loose powder anti-caking agent, pressed powder smoothing agent, blush and eyeshadow powder additives, lipstick hydrophobic agent, sunscreen powder additives, foundation pressing additives, makeup anti-blocking agents, skin care powder conditioning agents, etc.

Why it can be used for this purpose: Calcium stearate hydrophobic fine powder acts as an anti-caking agent (moisture-proof and anti-caking), a smoothing agent (for smooth spreading), and a hydrophobic agent (waterproof and sweat-proof) in powder cosmetics. Its layered lubricating structure has good compatibility with powder and is a standard powder additive for pressed and loose powder cosmetics such as loose powder and pressed powder (included in INCI Calcium Stearate).

12. Anti-caking agents for powder and granular foods (food industry, core food applications)

Application areas: Powder and granular food processing.

Corresponding products: anti-caking agents for salt, spices, chicken bouillon powder, soup powder, sugar powder, milk powder, solid beverage powder, cocoa powder, baking premix powder, and protein powder, etc.

Why it can be used in this way: Fine calcium stearate powder coats the surface of powder particles to form an isolation layer and absorb moisture, preventing the formation of liquid bridges and crystal bridges between particles, preventing powders such as salt, spices, and milk powder from clumping, and maintaining free flowability; FDA 21 CFR 184.1229 explicitly approves it as an anticaking agent, and it is a commonly used E470a component for anticaking of powdered foods.

13. Confectionery spreading agents and polishing agents (confectionery industry)

Application areas: Hard candy and polished confectionery industry.

Corresponding products: Smarties (candy bean) dispersant, Jawbreakers (hard candy ball) dispersant, polishing sugar coating aid, hard candy anti-blocking agent, candy granule dispersant, sugar-coated pellet polishing agent, chocolate bean polishing aid, etc.

Why it serves this purpose: The layered lubricating structure of calcium stearate makes candy particles smooth, non-sticky, and flowable during manufacturing and storage (Wikipedia clearly states that it is a flow agent for candy beans and hard candy balls), while also giving the polished coating a glossy finish. It is a standard powder additive for hard candy.

14. Lubricant for releasing compressed candies and health food tablets (in the field of compressed products)

Application areas: Manufacturing of compressed candy and health food products.

Corresponding products: Candy release agent, peppermint lozenge lubricant, health food tablet release agent, calcium chewable tablet lubricant, vitamin tablet release agent, lozenge lubricant, tablet die anti-sticking agent, etc.

Why it can be used in this way: Calcium stearate forms a low-shear lubricating film between the tableting die and the tablet, reducing the demolding force and die wear, making the tablets intact, smooth, and easy to demold; its non-hygroscopicity and chemical inertness do not affect the stability of the tablets, making it a commonly used demolding lubricant for compressed candies and health food tablets.

15. Gum base components (gum industry)

Application areas: Chewing gum and bubble gum manufacturing.

Corresponding products: chewing gum base components, bubble gum base additives, gum base processing lubricants, sugar-free chewing gum base, gum base softening additives, etc.

Why it can be used for this purpose: FDA 21 CFR 184.1229 explicitly allows calcium stearate to be used in chewing gum as a gum base component and processing aid to improve the processing rheology and product texture of the gum base. Its fatty acid salt structure has good compatibility with gum base resin and is a non-toxic and compliant chewing gum base additive.

16. Food emulsifiers and binders (food processing industry)

Application areas: Baking, beverage, pudding and sauce food processing.

Corresponding products: emulsifying stabilizers for baked goods, emulsifying aids for non-alcoholic beverages, binders for ready-to-eat puddings, stabilizers for meat gravy sauces, emulsifiers for sweet sauces, texture modifiers for gummies, stabilizers for condiments, emulsifiers for instant drinks, etc.

Why it can be used in this application: The amphiphilic structure of calcium stearate (hydrophobic long chain + polar calcium end) can be oriented at the oil-water interface, reduce interfacial tension, stabilize the emulsion system and improve texture; FDA 21 CFR 184.1229 approves it as an emulsifier and binder, allowing its use in baked goods, non-alcoholic beverages, puddings, gravy sauces, sweet sauces and fudge, etc. (limited to 0.2%-2% by category).

1.7 . Anticaking agents for animal feed (feed industry )

Application areas: Livestock and aquatic feed processing.

Corresponding products: anti-caking agents for pig feed, anti-caking agents for chicken feed, powder additives for cattle feed, anti-caking agents for premixed feed, flowable agents for pelleted feed, anti-caking agents for aquatic feed, anti-caking agents for feed carriers, etc.

Why it can be used for this purpose: Calcium stearate is a non-toxic, hydrophobic powder that is coated on the surface of feed granules to prevent moisture absorption and clumping, and to maintain feed flow and uniform mixing. It is approved by the FDA 21 CFR 573.320 as an animal feed additive (anti-caking agent) for the anti-caking treatment of livestock, poultry and aquatic feed.

18. Fertilizer anti-caking agents (agricultural field )

Application areas: Fertilizer production and storage.

Corresponding products: compound fertilizer anti-caking agent, urea anti-caking agent, ammonium phosphate anti-caking agent, fertilizer granule coating agent, water-soluble fertilizer dispersing agent, blended fertilizer (BB fertilizer) anti-caking agent, controlled-release fertilizer coating agent, etc.

Why it works for this purpose: The hydrophobic coating of calcium stearate coats the surface of fertilizer granules, preventing the granules from absorbing moisture, sticking together, and clumping. It maintains the free flow of fertilizer during storage, transportation, and application, and is a commonly used anti-caking agent for fertilizer granules in fertilizer production.

Summarize

Calcium stearate (Ca(C18H35O2)2, CAS 1592-23-0, molecular weight 607.03) is a universal metallic soap used in a wide range of applications, from PVC pipes to concrete blocks, from grease to waterproof canvas, and from loose powder and lipstick to salt and milk powder. It boasts six key properties: long-chain lubrication, acid removal, hydrophobic film formation, calcium-zinc synergy, fiber thickening, and powder anti-caking. It has mature applications in heat stabilizers, plastic lubricants for demolding and acid removal, rubber softeners, grease thickeners, concrete waterproofing and salt control, paper coating lubrication, fabric waterproofing, coating matting agents, metal wire drawing and pencil/crayon lubrication, industrial defoamers, cosmetic powder anti-caking and slip agents, powder food anti-caking agents, candy flow polishing, compressed candy and health tablet demolding lubrication, chewing gum base components, food emulsifying adhesives, tablet lubricants, animal feed anti-caking agents and fertilizer anti-caking agents, etc. Among them, PVC heat stabilizers (calcium zinc lead-free system) is its absolute main track, while concrete waterproofing, food anti-caking, cosmetic powder additives and tablet lubricants are four high value-added directions.