I. Product Overview
Antioxidant 2246 is a high-efficiency non-polluting antioxidant with excellent performance. As one of the superior varieties in hindered phenolic antioxidants, this compound possesses outstanding antioxidant properties and extensive application adaptability. It is an indispensable important additive in industrial fields such as rubber, plastics, and petroleum.
II. Basic Information
Chemical Name: 2,2'-Methylenebis(4-methyl-6-tert-butylphenol)
CAS: 119-47-1
Molecular Formula: C₂₃H₃₂O₂
Molecular Weight: 340.5
Molecular Structure：
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This compound has multiple aliases, including Antioxidant 2246, 2,2'-Methylenebis(6-tert-butyl-p-cresol), Anti-aging Agent MBP, etc. In the international market, it also has various trade names such as Vulkanox BKF, Cyanox 2246, Wellnox 2246, etc.
III. Physicochemical Properties
Appearance and Form
The pure product is a white to off-white crystalline powder. When exposed to air for a long time, the color may become slightly yellowish-pink, but this color change does not affect its performance. The product has a slight phenolic odor.
Key Physical Parameters
Melting Point: 123-133°C
Boiling Point: 428.6°C (760mmHg)
Density: 1.04-1.09 g/cm³
Flash Point: 181-195°C
Bulk Density: 300-308 kg/m³
Vapor Pressure: <1 hPa
Solubility
Antioxidant 2246 exhibits obvious selectivity in its solubility in various solvents. It is easily soluble in multiple organic solvents, including acetone (175g/100ml, 20°C), ethanol (154g/100ml), ethyl acetate (134g/100ml), toluene (62g/100ml), benzene (46g/100ml), etc., but has lower solubility in n-heptane (8g/100ml) and extremely poor solubility in water (only 7μg/L, 20°C), belonging to practically insoluble.
IV. Synthesis Method
The preparation process of Antioxidant 2246 mainly includes two main steps:
Step 1: Preparation of Intermediate
Using p-cresol as raw material, 2-tert-butyl-4-methylphenol is prepared through alkylation reaction with isobutylene at about 60°C under the catalysis of 732# strong acid ion exchange resin. After the reaction is completed, the catalyst is filtered out, and the filtrate is treated with methanol-sodium hydroxide solution to precipitate by-product Antioxidant 264.
Step 2: Condensation Reaction
The obtained 2-tert-butyl-4-methylphenol undergoes condensation reaction with paraformaldehyde in aqueous emulsion solvent, with concentrated sulfuric acid and sodium dodecylbenzene sulfonate in the reaction system. Optimized process parameters: n(2-tert-butyl-4-methylphenol):n(paraformaldehyde)=2:1.06, reaction temperature 83-86°C, reaction time 4.5 hours, yield exceeding 75%. After the reaction product is neutralized, filtered, washed, dried, milled, and packaged, the finished product is obtained.
Each ton of product consumes approximately 1600kg of p-methylphenol, 1600kg of isobutylene, and 400kg of formaldehyde (40%).
V. Performance Characteristics
The reason why Antioxidant 2246 has become a widely used general-purpose antioxidant is mainly due to its following excellent performance:
● High Thermal Stability: Able to maintain good antioxidant effects in high-temperature environments
● Significant Antioxidant Effect: Its antioxidant performance is superior to Antioxidant 264
● Non-Polluting: No pollution to products, non-toxic, non-discoloring, especially suitable for light-colored and bright-colored products
● Non-Blooming: No surface precipitation phenomenon during use
● Good Oil Solubility: Good dispersibility in polymer matrices, easy to operate
● Not Volatile Loss: Low volatility ensures long-term stability
● Excellent Compatibility: No influence on vulcanization and plasticity of rubber, no destabilizing effect on latex
● Low Dosage: Usually an addition of 0.1-1.0% can achieve good protective effect
VI. Application Fields
1. Rubber Industry
Antioxidant 2246 is an ideal antioxidant for synthetic rubber, latex, and natural rubber. As one of the superior varieties in phenolic antioxidants, rubber products with this antioxidant added have the following functions:
Anti-Thermal Oxidation Aging:Effectively captures free radicals in rubber, inhibits chain oxidation reactions, delays the aging process of rubber at high temperatures, and prevents rubber from becoming hard and brittle due to oxidation
Prevention of Photo-Ozone Aging:Enhances the weatherability of rubber, reducing aging phenomena caused by natural factors such as sunlight and humidity changes
Prevention of Damage from Repeated Deformation:Can enhance the elasticity of rubber and reduce cracks and fractures caused by mechanical stress
Passivation of Salts of Variable-Valent Metals:Rubber products often contain variable-valent metal ions such as copper and iron. Antioxidant 2246 can undergo complexation reactions with these metal ions to form stable compounds, inhibiting metal-accelerated oxidation
Particularly suitable for light-colored and colored rubber products, as well as latex-impregnated products, medical and sanitary latex products, etc.
2. Plastics Industry
In the plastics industry, Antioxidant 2246 can prevent thermal aging and photo-aging of multiple plastics. Specific applications include:
Polyolefins:Polyethylene, Polypropylene
Engineering Plastics:ABS resin, Polyoxymethylene (POM), Chlorinated polyether, Polyurethane
Others:Impact-resistant polystyrene, Cellulose resin
This antioxidant can significantly improve the heat resistance of plastic products, maintain the color and transparency of products, and extend service life. The dosage is 0.1-1.0%.
3. Petroleum Products
As an antioxidant additive for petroleum products, Antioxidant 2246 possesses:
Other Applications
Antioxidant 2246 can also be used in food packaging materials, medical devices, and other products requiring high safety. Its low toxicity characteristics give it significant advantages in these applications.
VII. Toxicity and Safety
Toxicity Data
Rat oral LD₅₀: 4880-6500 mg/kg
Rat dermal LD₅₀: >2000 mg/kg
According to acute toxicity classification, Antioxidant 2246 belongs to low-toxicity compounds.
Regulatory Certification
Approved for use in food packaging materials in the United States, Germany, the United Kingdom, Italy, Japan, and other countries
Japan's maximum allowable dosage:Polyethylene and polypropylene 0.1%, Polystyrene 0.4%, AS resin 0.6%, ABS resin 2%, Polyvinyl chloride 2%
US FDA regulation:For polyolefins not exceeding 0.1%, products must not contact food containing grease on the surface
Complies with US FDA 175.105 (Food packaging adhesives) and 177.2600 (Rubber articles intended for repeated contact with food)
VIII. Storage and Packaging
Storage Conditions
Products are stored in a cool, dry place, avoiding high temperatures and humidity. Packaged products should avoid direct sunlight. Under appropriate storage conditions, products can maintain stability and effectiveness for more than 12 months.
Packaging Form
Packaged in 20kg composite bags, with a net weight of 20kg per bag, lined with polyethylene bags to ensure product safety during transportation and storage. Other packaging specifications can be provided according to customer requirements.
Safety Warnings
Hazard Symbol: Xi (Irritant), Xn (Harmful)
Hazard Class Code: R36 (Irritating to eyes)
Safety Instructions: S26 (In case of contact with eyes, rinse immediately with plenty of water and seek medical advice), S36 (Wear suitable protective clothing)
IX. Product Quality Standards
Main technical indicators for industrial-grade Antioxidant 2246 include:
Appearance: White to off-white powder
Initial Melting Point: ≥120.0°C
Loss on Drying: ≤0.5%
Ash Content: ≤0.3%
Fineness (through 100-mesh sieve): ≥99.5%
Content: ≥95.0%
X. Market and Development Prospects
As a widely used general-purpose antioxidant, Antioxidant 2246 has numerous manufacturers worldwide. According to statistics, there are about 435 companies producing this product globally, with 341 in China, indicating that China has become an important producer and consumer of this product.
With increasingly strict environmental regulations and continuous expansion of industrial application fields, Antioxidant 2246 has broad application prospects in industries such as rubber, plastics, and petroleum due to its low toxicity, high efficiency, and non-polluting characteristics. Particularly in high-end food packaging materials, medical devices, and other fields with extremely high safety requirements, Antioxidant 2246 will play an even more important role.
Conclusion
With its excellent antioxidant performance, good compatibility, low toxicity, and extensive application adaptability, Antioxidant 2246 has become an indispensable important additive in industries such as rubber, plastics, and petroleum. With the development of materials science and the expansion of application fields, Antioxidant 2246 will inevitably play an even more important role in improving product quality, extending service life, and promoting sustainable industrial development.
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