Stearic Acid CAS 57-11-4

What Stearic Acid Is

Stearic acid is a natural fatty acid with an 18-carbon saturated chain, derived from vegetable and animal fats and refined by pressing and distillation. At room temperature it is a white waxy solid that melts just above 50 °C. Because it is cheap, stable and mildly reactive, it is one of the most common industrial fatty acids across rubber, plastics, cosmetics and food.

Picking the Right Grade

Stearic acid is sold by grade number, and the two most common are 1860 and triple-pressed. Rubber grade 1860 has a slightly higher iodine value and looser color limit, does its job perfectly in rubber and PVC, and costs less. Triple-pressed grades are pressed three times for lower color, lower iodine value and higher purity, which is what cosmetic, food and candle makers ask for when appearance and odour matter. If you are not sure, tell us the application and we will point you to the right grade rather than overselling.

Where It Is Used

• Rubber. The standard vulcanization activator alongside zinc oxide in almost every sulfur-cured compound, from tires to seals, and an internal lubricant that eases processing and mold release.
• Plastics. Internal lubricant and release agent in PVC pipe and profiles, polyolefins and engineering plastics, improving flow and surface finish.
• Cosmetics and soap. Emulsifier, thickener and bodying agent in creams, lotions, shaving foam and bar soaps, and a pearlescent contributor.
• Candles, food and industry. Hardener and opacifier in candles, mold release and anti-caking aid in food, and feedstock for stearates, rubber and metal processing aids.

Standard Rubber Grade Specifications

Packaging, Storage and Ordering

• Packed in 25 kg PE-lined kraft bags, with beads and bulk bags on request. Keep sealed below 35 °C and away from heat, flame and oxidizers; the flakes soften and clump above the titer point.
• The product is non-hazardous for normal ocean and land transport. Dust from powder grades can irritate the airways, so wear a mask and goggles when handling.
• COA, TDS and SDS come with every order, samples are available, and quotes go out within one working day. It is a core partner of Rubber Accelerator TBBS CAS 95-31-8 in the same cure package, and pairs with Antioxidant SP CAS 61788-44-1 in rubber compounds.

FAQ

Q: What does it do in rubber?

A: It reacts with zinc oxide to activate the sulfur cure, and lubricates the rubber and mold.

Q: Rubber grade or triple pressed?

A: Triple pressed is purer for cosmetics and food; industrial 1860 suits rubber and PVC.

Q: How do I confirm the grade I need?

A: Check acid value and titer on the COA, and match the form, flakes or beads, to your dosing.