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-308 has a qualitative 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 |
Pure polyester <acid value 30-35mgKOH/g;SJ-4#ET/9336> |
450 | Pure polyester <acid value 30-35mgKOH/g;SJ-4#ET/9336> |
450 |
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 | 7 | T-302B | 15 |
Gloss: 2-5% Impact: 50kg.cm(direct/reverse) | Gloss: 10-20% Impact: 50kg.cm(direct/reverse) | ||
Curing condition: 200℃×10min |
T-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 value around
30-35 mgKOH/g.
1.2 T-308 to polyester ratio is 75/25 when use polyester with acid value
around 20-25
mgKOH/g.Normally select lower acid value polyester to get cost reduction and more
smoothness film appearance
T-318 is a hydroxyalkylamide curing agent with modified luster used with T-308.In mass production, we always fix the usage of pure polyester, T-308 and catalyst T-62, and only control gloss by the dosage of T-318 or TGIC.
Using 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.
When 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 ③ In conjunction with 1-2% of T-302B, gloss stability, anti-scratch resistance and smoothness on the surface will be improved.
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 is at least 2 years when ambient temperature is below 30℃.