ADDITIVES | ANTIOXIDANTS & STABILISERS
ties, and Martin Pavlik, Addivant’s recently-appoint- ed Global Director of Business Development (he moved to the company in March, after almost 12 years at Dow Chemical) said in late August that approval from the Mercosur Southern Common Market had just been granted. “Weston 705 is currently the only sustainable globally registered liquid AO for polyolefins on the market,” he says. Weston 705 is targeted squarely at polyethyl-
Figure 5: Comparison of the effect of different AO packages on yellowing in polypropylene after one, three, and five extrusion passes Source: Baerlocher
ing issues,” says Robert L Sherman, technical director for Baerlocher USA’s Special Additives division. “Innovative solutions are particularly critical for stabilising recycled polyolefin content, meeting regulatory requirements for safety in food packaging, and delivering improved colour and polymer stability.” This effect is shown in Figure 5. Baerlocher says that even though they have been used for years as secondary antioxidants for polyolefins, particularly for melt phase stabilisation, phosphite additives can present solubility issues. “They can come out of solution and cause plate-out on extrusion equipment and polymer parts,” it says. “New Baeropol DRS 6812 additive delivers excellent solubility and optimises hydrolytic stability for consistent performance.” The new antioxidant is also claimed to offer “exceptional” compounding flexibility. It can directly replace phosphites as a 1:1 drop-in substitute, or act as a synergist to reduce the loading of phosphites. It is even said to allow the use of lower-cost phosphites while maintaining desired performance. Baeropol DRS 6812 contains synergistic polymer
Right:
Baerlocher’s Baeropol DRS 6812 in “prill” form. Individu- al particles are about the size of sugar granules
stabilisation additives that improve melt stability in polyolefin resins and compounds, as well as polymer colour and processing consistency, compared to standard phosphites. Baerlocher adds that it also extends useful polymer life. Baeropol RST chemistry can be suitable for generally recognised as safe (GRAS) applications, making it applicable for indirect food contact.
Thoughts for food Addivant notched up another success for its Weston 705 antioxidant when it obtained clearance for use of this nonylphenol-free liquid phosphite for food-contact applications in the Mercosur region of South America. Weston 705 already has approvals from US, European, and Chinese regulatory authori-
46 COMPOUNDING WORLD | September 2018
www.compoundingworld.com
enes, although it is also being used in some TPEs. Pavlik says Addivant is working on obtaining food contact approvals for its use in polypropylene, but this will take around 18 months.
Addivant has also begun developing a new solid
AO with improved efficiency, based on what it describes as a novel sustainable chemistry. Market launch is expected to be around 2020. “We think liquids are the most effective for a variety of reasons, but a large part of the industry is still operating with solid antioxidants, so we are committed to developing as quickly as possible a new complete solution system for that sector,” says Pavlik. “Our aim is to have a system with a safety profile that complies with current and likely future regulatory requirements and which in any case will be superior to any solid system currently available.” Pavlik notes that most solid AO systems for polyolefins are combinations of a phenolic primary antioxidant and a phosphite secondary antioxidant. “Phosphites are coming under increasing scrutiny,” he says. “In three to five years, today`s molecules may undergo a similar phase-out as TNPP recently did. So we are conducting studies on possible alternatives. This is why we developed Weston 705 in the first place. At the end of the day, Addivant wants a portfolio of the safest products possible.” Pavlik says that the expected merger of Addivant
with SI Group, another major manufacturer of performance additives and intermediates, will
PHOTO: BAERLOCHER
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82
