1.Description:
T-308 is a glycidyl containing solid acrylic resin designed for applying in low acid value saturated carboxyl polyester powder coatings system as hardener using compatibility difference to achieve matt gloss. T-308 can produce 1-10% of low gloss exterior durable powder coatings with good coverage, excellent weather resistance, salt spray resistance, high temperature resistance and anti-yellowing characteristics. Compared with the competitive products both home and abroad, T-308hasaqualitative improvement in leveling, scratch resistance, impact strength and gloss stability.
| Appearance | transparent granule |
| Soft point (℃) | 135-145 |
| Epoxy equivalent weight (EEW) | 650-750 |
| Solid content(%) | >99 |
3.Formula reference:
| Pure polyester | Pure polyester |
| Matting agent T-308 130 | Matting agent T-308 110 |
| Hardener T-318/TGIC 8/12 | Hardener T-318/TGIC 10/15 |
| General flowing agent T-988 10 | General flowing agent T-988 10 |
| Benzoin 3 | Benzoin 3 |
| Barium sulfate 400 | Barium sulfate 400 |
| Black Carbon 7 | Black Carbon 7 |
| Catalyst T-62 1 | T-302B 15 |
| Gloss: 2-5% Impact: 50kg.cm(direct/reverse) | Gloss: 10-20% Impact: 50kg.cm(direct/reverse |
| Curing condition: 200℃×10min | |
4.Precautions:
①T-308 and TGIC can both be used as curing agent with carboxyl polyester.1.1 T-308 to polyester ratio is 70/30 when use polyester with acid valuearound30-35 mg KOH/g. 1.2 T-308 to polyester ratio is 75/25 when use polyester with acid value around20-25 mg KOH/g. Normally select lower acid value polyester to get cost reduction and more smoothness film appearance
② T-318 is a hydroxyalkyl amide curing agent with modified luster used with T-308.Inmassproduction, we always fix the usage of pure polyester, T-308 and catalyst T-62,andonlycontrol gloss by the dosage of T-318 or TGIC.
③Using 0.05~0.2% T-62 in formulations above can make film mechanical performance better, gloss lower and stable, with reduced cost. But when using too much, levelling would be affected.
④When producing powder coating with over 10 degree, necessary attentions should be paid in the following aspects : ①baking schedule should remain the same between powder manufacturers and end-users ②production process should be fixed ③In conjunctionwith1-2% of T-302B, gloss stability, anti-scratch resistance and smoothness on the surface will be improved.
5.Package and storage:
Packaging with PE lined Kraft paper bags, Net weight is 25kg per bag. Store in cool and dry place to avoid moisture. According to our experience, the period of validity of this product isatleast2 years when ambient temperature is below 30 ℃.