Stearic acid, that is, octadecanic acid, is a fatty acid widely present in nature, with the chemical properties of general carboxylic acid, English name (Stearic Acid), structure simplified: CH3 (CH2) 16COOH, produced by oil hydrolysis, white waxy transparent solid or slightly yellow waxy solid, can be dispersed into powder, slightly with butter odor.
There are varying levels of stearic acid in almost all oils and fats, and the content in animal fats is higher, such as up to 24% in butter, less in vegetable oil, tea oil is 0.8%, palm oil is 6%, but the content in cocoa butter is as high as 34%.
Stearic acid 1860
Stearic acid is mainly used in the production of stearates such as sodium stearate, magnesium stearate, calcium stearate, etc., but also widely used in the manufacture of cosmetics such as alabaster and cold cream, playing an emulsifying effect, so that it becomes a stable white paste. Stearic acid is also the main raw material for the manufacture of almond honey and milk liquids.
<h1 class="pgc-h-arrow-right" > first, the physical and chemical properties of stearic acid</h1>
1.1. Basic Information
Density: 0.84
Boiling point 3: 61 °C(lit.)
Melting Point: 67-72 °C(lit.)
Molecular Formula: C18H36O2
CAS number: 57-11-4
Molecular Weight:284.47700
Flash point: >230 °F
Exact mass: 284.27200
PSA：37.30000
LogP：6.33250
Appearance shape: white solid with a mild odor
Vapor pressure: 1 mm Hg ( 173.7 °C)
Refractive index: 1.4299
Water solubility: 0.1-1 g/100 mL at 23 ºC
Stearic acid structure
1.2. Molecular structure
Molar refractive index: 87.00
Molar volume (cm3/mol): 320.2
Isargon ratio (90.2K): 770.0
Surface tension (dyne/cm): 33.4
Polarization rate (10-24cm3): 34.49
1.3. Stability
1.3.1. Pure products are white soft pieces with luster.
1.3.2. Slightly soluble in cold water, soluble in alcohol, acetone, easily soluble in benzene, chloroform, ether, carbon tetrachloride, carbon disulfide, pentyl acetate and toluene. innocuity.
1.3.3. Present in flue-cured tobacco leaves, burley tobacco leaves, spice tobacco leaves, and smoke.
1.3.4. Are fatty acids that make up stearin.
<h1 class="pgc-h-arrow-right" > second, stearic acid safety information</h1>
Personal Protective Equipment: dust mask type N95 (US); Eyeshields; Gloves
Hazard Code (Europe): F:Flammable
Risk Statement (Europe): R11; R36/37/38
Safety statement (Europe): S37/39-S26-S16
Dangerous goods shipping code: NONH for all modes of transport
WGK Germany: 3
RTECS number: WI2800000
HS code: 2915701000
<h1 class= "pgc-h-arrow-right" > three, stearic acid preparation (production method).</h1>
The production methods of industrial stearic acid are mainly divided into two methods: fractionation method and pressing method. A decomposer is added to the hardening oil, and then hydrolyzed to obtain fatty acids, and then washed, distilled, and decolored to obtain the finished product. At the same time by-product glycerol.
3.1. Fractionation method In the hydrolyzed pot, add cottonseed oil hardening oil 6t, hydrolyzed agent cresol sulfonic acid stearate and naphthalene sulfonic acid stearate 120kg. After adding steam to the oil layer is transparent, add 4200kg of water. Continue to heat to boiling, react at atmospheric pressure for 7.5 h, clarify 0.5 h, and separate the lower glycerol water. After that, add 120kg of hydrolysate, heat it into steam to make the oil layer transparent, add 3600kg of water, the reaction is about 10h, when the mixed acid price reaches 190mg KOH/g or more, it is the end of hydrolysis. After that, it was clarified for 0.5 h, and after separating the glycerol water, added 7g of salt and 3600kg of water for washing. Then wash it with 14 kg of salt and 4200 kg of water for secondary water. Clarification is 0.5 h after washing in the first step and 2 h after washing in the second step. After draining the lower layer of acid water, take the upper layer of mixed fatty acids and set aside.
Stearic acid preparation (production method)
2000kg of mixed fatty acids are added to the distillation kettle for reduced pressure fractionation, the kettle temperature is 250-255 °C, the tower temperature is 210-220 °C, the top temperature is 200-210 °C, and the top residual pressure is 0.53-0.93 kpa. After the infeed, discharged and discharged materials are balanced, they are transferred to continuous operation, with 100% infeed, 40% outfeed and 60% indoctrine. The feed is used to make tertiary stearic acid. After the discharge is analyzed with an iodine value of 2mgl/100g or less, 1000kg of stearic acid and 3kg of 92.5% sulfuric acid are put into the pickling pot in turn and boiled and washed. After cutting the acid foot, take 450kg of stearic acid into the decolorizing pot and heat it to 190 °C, and add 150ml of chemical soda ash and 11kg of dried clay successively, and then decolorize about 105°C and decolor for about 45min under reduced pressure stirring. After pressing the filter and stirring molding, the first-level stearic acid is obtained.
The glycerol water separated during hydrolysis is neutralized with lime milk at 80-100 °C, and refined glycerol can be obtained by suction filtration concentration, filter press, vacuum distillation, activated carbon decolorization and filter press.
3.2. Pressing method Taking animal and vegetable oil as raw material, the first-class stearic acid is prepared by high-pressure hydrolysis, washing, decompression distillation, pressing, bleaching crystallization and other processes under the presence of hydrolyzed agents (such as zinc oxide).
3.3. In the presence of decomposing agents (benzene, naphthalene and other sulfonated mixtures), the hardened grease, bovine grease or sheep grease is hydrolyzed, and then acidified, distilled, pressed, acid-eluted to obtain the finished product.
3.4. Hydrogenation with oleic acid.
3.5. The synthetic fatty acids C10 ~ C20 and C18 ~ C20 are divided into raw materials by melting, pickling (with 1% sulfuric acid) casting, pressing, melting, pickling, dehydration crystallization.
<h1 class="pgc-h-arrow-right" >4. The use and application field of stearic acid</h1>
4.1. In the rubber industry, it plays the role of vulcanizing active agent, softener, dispersant, etc.;
4.2. Can be used as a thickener of lubricating oil, a smoothing agent for paint, a drying agent, a delaminant for plastics, a polishing agent for textiles, etc.;
4.3. Production of PVC pipe pipes and gusset industry, using stearic acid and calcium stearate;
4.4. The production of cable electric material can use stearic acid, and zinc stearate is used at the same time;
4.5. Stearic acid and barium stearate can be used in the artificial leather industry;
4.6. In the stationery and educational supplies industry, stearic acid is an important raw material for the manufacture of crayons, stearic acid can improve the gloss opacity of crayons, and the amount of stearic acid used in crayons accounts for 30%. In addition, stearic acid can also be used in the refill of the pencil, increasing the hardness and slip of the refill to improve the coloring force and adhesion. Stearic acid also acts as a gelling agent for solid glue;
4.7. In the grease industry, stearic acid is the main raw material for the manufacture of soap-based, mainly producing lithium-based grease and calcium-based grease;
4.8. The ultra-fine active calcium carbonate industry uses stearic acid to increase the activity, and the stearic acid is used as a medium when producing active calcium carbonate;
4.9. Stearic acid is used in the formulation of the shoe polish industry, stearic acid in the formula of the metal polishing agent industry, and stearic acid can be used in the automotive varnish and floor polishing agent industry;
4.10. Glass fiber drawing and metal drawing industry, stearic acid plays the role of mold release agent, lubricant;
4.11. Compound fertilizer industry, stearic acid can be used as compound fertilizer anti-caking agent;
4.12. Stearic acid is used in the waterproof material industry to improve the waterproofness of materials;
4.13. Abrasives and abrasives in the industry with a small amount of stearic acid;
4.14. Stearic acid is used in the footwear industry, which can improve the wear resistance of the sole, and it is also possible to use hard salt foaming agent;
4.15. Stearic acid can be used in the production of masterbatch fillers;
4.16. Stearic acid is used in the plastics industry as a plasticizer, stabilizer and lubricant;
4.17. Fine art pigment industry can use small amounts of stearic acid and glycerin;
4.18. Stearic acid can be used in the production of rubber rollers, tape industry and insulation material industry;
Stearic acid application areas
<h1 class="pgc-h-arrow-right" >5, stearic acid customs information</h1>
Chinese Overview: HS: 2915701000 Stearic Acid [90% purity and above in dry weight] VAT rate: 17.0% Rebate rate: 9.0% Regulatory conditions: AB Minimum Tariff: 7.0% General Tariff: 50.0%
Declaratory elements: product name, ingredient content, use, stearic acid and soft lipid acid content
Regulatory conditions: A. Customs clearance form for inbound goods B. Customs clearance bill for outbound goods
Inspection and quarantine: R. Import food hygiene supervision and inspection S. Export food hygiene supervision and inspection
Summary：HS:2915701000 stearic acid VAT:17.0% Tax rebate rate:9.0% Supervision conditions:AB MFN tariff:7.0% General tariff:50.0%
<h1 class="pgc-h-arrow-right" >6. Storage method</h1>
6.1.200 type stearic acid is packed in cardboard boxes. Type 800 stearic acid is packed in a woven bag lined with plastic bags.
6.2. Store in a cool, dry and ventilated place, pay attention to keep away from fire sources and oxidants. Stored and transported in accordance with general chemical regulations.
<h1 class="pgc-h-arrow-right" > seven, stearic acid part of the literature</h1>
7.1.Study of the persistence of the anti-inflammatory effect observed after application of preparations containing organic ultraviolet filters.
Int. J. Pharm. 476(1-2) , 160-3, (2015)
7.2.Abiogenic Syntheses of Lipoamino Acids and Lipopeptides and their Prebiotic Significance.
Orig. Life Evol. Biosph. 45 , 427-37, (2015)
7.3.Structural insights into methanol-stable variants of lipase T6 from Geobacillus stearothermophilus.
Appl. Microbiol. Biotechnol. 99 , 9449-61, (2015)
7.4. Zhou Yuehong, Tang Yongwei, Preparation method of isododecanoster stearate, CN 200710044268, application date2007-07-26
7.5. Geng Youyong, Jing Xiaodong, Rong Ruogui, Stearic Acid Polyether and Preparation Method Thereof, CN 201410535929, Application Date2015-01-07
7.6. Xi Zhou, Haiyan Li, Youzhi Dai, A Method for Synthesizing Calcium Stearate by Aqueous Phase One-Step Method, CN 201410685213, Application Date2014-11-25