Antioxidant 1520

AO1520

Antioxidant 1520(2, 4-bis (n-octylthiomethylene) -6-methylphenol) is a new type of antioxidant, its phenol hydroxyl can catch free radicals, thioether can decompose hydroperoxides, with intramolecular synergistic effect, can be used as polymers, vegetable oils, synthetic lubricants, etc., to prevent oxygen, heat, light or high-energy radiation damage to organic matter. In particular, Antioxidant 1520 can be used to resist oxidative aging during storage of various elastomer raw materials, to prevent gel formation in butadiene rubber, to prevent oxidative coloring in rigid styrene polymers, to improve the stability of storage and processing at high temperatures in styrene butadiene rubber, to prevent aging under processing conditions in isoprene styrene block copolymers, to prevent gel formation in elastomers and private mixtures Color change during storage and transportation.

Application

Antioxidant 1520 is a new high molecular weight liquid antioxidant, mainly used in butadiene rubber, styrene butadiene rubber, ethylene propylene rubber, nitrile rubber, thermoplastic elastomer and other synthetic rubber, its dosage is small, the antioxidant effect is good, can improve the stability of plastics or synthetic plastics. It is an antioxidant, which realizes the transformation of rubber products from universal to green.

Synthesis method

At present, the synthesis method of antioxidant 1520 is mainly Mannich alkali method, that is, o-methylphenol, n-octylmercaptan, formaldehyde or paraformaldehyde obtained by Mannich reaction.

The above synthesis method includes two process routes in actual operation, one is o-methylphenol and excessive polyformaldehyde, dimethylamine first reaction to prepare mannienine 2-methyl-4, 6-bis (dimethylamine methyl) phenol, and then react with mertan, dimethylamine removal and formation of antioxidant 1520, and then separation and purification of the product method, also known as the two-step method. Typical literatures include US3832328, EP428973A1, US5116894, etc. The reaction process of this method is relatively complicated, and it needs to use a lot of dimethylamine, the preparation and purification process of the intermediate also needs more time, and the yield is relatively low, which is not suitable for industrial production.

An optimized synthesis method of antioxidant 1520 consists of the following steps:

1) O-cresol, n-octylmercaptan, formaldehyde, diethanolamine and solvent were added to the reactor, and then acid was added to adjust the pH to 1-5 for reflux reaction;

2) Cooling and standing to stratify, discharge the lower water phase from the lower outlet of the reactor, then add iodomethane and CuI, and then reheat to make the reaction;

3) Cool, filter to remove insoluble matter, add appropriate amount of formic acid and reheat to 30-60℃, stirring;

4) After washing with water, vacuum distillation, drying, ready.

Qingdao yihoo polymer technology co. ltd. is committed to the production and supply of a variety of efficient additives used in plastics and coatings.  Product types covers antioxidants, light stabilizers, UV absorbers, flame retardants, etc., and products have earned more than 100 overseas customers trust.

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