Antioxidant 245

Characterization

Antioxidant 245 is a sterically hindered phenolic antioxidant particularly suitable for organic substrates. It protects the substrates against thermo-oxidative degradation during manufacturing, processing and end-use. Antioxidant 245 is odorless, of low volatility, has a good color stability and exhibits high extraction resistance.

Physical Properties

Applications

Antioxidant 245 is effective in styrene polymers, particularly impact modified polystyrenes, ABS, MBS, SB and SBR-latices as well as in POM homo- and copolymers. It is also very useful for the stabilization of polyurethanes, polyamides, thermoplastic polyesters, PVC and other polymers. In addition to imparting thermostability to the finished polymer Antioxidant 245 is effective as chain stopper during PVC polymerization.

Features/benefits

Antioxidant 245 can be used in combination with other additives such as costabilizers (e.g. thioesters, phosphites, phosphonites, lactones), light stabilizers, and other functional stabilizers. The effectiveness of the blends of Antioxidant 245 with IRGAFOS 168 (Irganox B-blends) is noteworthy.

Guidelines for use

Already 0.05 – 0.1 % of Antioxidant 245 provides long-term thermal stability tothe polymer. Concentrations up to 1.0 % can be used depending on the substrate and the requirements of the end application.

Uses

Antioxidant 245 is an ethylenebis (oxyethylene) bis-(3-(5-tert-butyl-4-hydroxy-m-tolyl)-propionate). It is an antioxidant for processing and long-term thermal stabilization. It has low volatility, good color stability and is odorless. Exhibits high extraction resistance. Antioxidant 245 protects the substrates against thermo-oxidative degradation during manufacturing, processing and end use. It is compatible with styrene polymers including polystyrenes, ABS, MBS, SB and SBR as well as POM homo-and copolymers. Also compatible with polyurethanes, polyamides, thermoplastic polyesters, PVC and other polymers. It is effective as chain stopper during PVC polymerization. Its recommended dosage level is 0.05-0.1% for long-term thermal stability. Concentrations up to 1.0% can be used depending on the substrate and the requirements of the end application.

Health & Safety

Antioxidant 245 exhibits a very low order of oral toxicity and does not presentany abnormal problems in its handling or general use.
Detailed information on handling and any precautions to be observed in theuse of the product(s) described in this leaflet can be found in our relevanthealth and safety information sheet.

Uses

Triethylene Glycol Bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate is used as a polymer antioxidant stabilizer in adhesives and polymers for food contact. Generally functions as an antioxidant in the chemistry of plastics.

Flammability and Explosibility

Not classified

Safety Profile

Questionable carcinogen withexperimental tumorigenic data. When heated todecomposition it emits acrid smoke and irritating vapors.

Synthesis

6386-39-6

51590-67-1

856335-90-5

36443-68-2

(2) To a 1 L four-necked flask equipped with a stirrer, a condenser tube, a thermometer and a nitrogen introduction tube were added 327.9 g (1.31 mol) of methyl 3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, 85.6 g (0.57 mol) of triethylene glycol and 0.9 g (0.00431 mol) of monobutyltin oxide. The mixture was reacted at 170 °C for 1 h while the resulting methanol was distilled. Subsequently, the reaction was continued for 8 h at a reduced pressure of 60-70 mmHg and nitrogen was continuously vented into the solution to ensure complete reaction. Upon completion of the reaction, 40.5 g of excess methyl 3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate was distilled by film distillation at 150-185 °C and 0.5-0.2 mmHg. This distillate can be used directly in the subsequent reaction. The reaction mixture was cooled to 115 °C and restored to atmospheric pressure by passing nitrogen, followed by addition of 260 g of toluene to dissolve the mixture homogeneously. The resulting solution was washed once with 200 g (0.11 mol) of 5% aqueous oxalic acid at 80 °C and twice with 200 g of water to separate the organic and aqueous layers. The organic layer was concentrated at 120 °C and 30 mmHg to give a pale yellow viscous substance. The mucilage was recrystallized with a mixed solvent of methanol-water to obtain 317.8 g of white crystalline triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]. The yield was 95% and the residual tin content was 2 ppm.

References

[1] Patent: US5081280, 1992, A