Modified dicyandiamide (OTB)
OTB is a modified dicyandiamide type curing agent with medium reactivity for high gloss epoxy resin based powder coatings. Due to its ideal distribution characteristics in the epoxy resin, it can provide a high quality finish at low curing temperatures.
Typical characteristics
color: white or off-white powder
content: >97%
Melting point: 139-143°C
Moisture: <0.5%
chloride: <0.4%
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Curing agent
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Ingredients
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suitable for powder coating types
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Typical addition amount phr
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Gloss @60℃
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shortest curing time
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Gel time @180℃/second
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Product Advantages
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OTB
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Replacement of dicyandiamide
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All epoxy coatings
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5-6
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90-100
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15min @160℃
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100-14305 phr (using type 3 epoxy)
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High gloss, clear epoxy coating
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Application
OTB is a medium-reactive curing agent for high-gloss epoxy powder coatings based on dicyandiamide derivatives. It is used in solid epoxy resin formulations without any further accelerators. In powder coating formulations based on solid bisphenol A epoxy resins, OTB is typically used at a dosage of 3.5%. Its advantages include complete solubility in the molten epoxy resin and very uniform distribution throughout the formulation, enabling the production of high-gloss, color-stable, and fast-reacting epoxy powder coatings.
Typical applications include car wheels, interior decoration, ceiling lights, door latches, fancy wood strips, auto parts, etc.
The recommended minimum curing time is 15 minutes at 160℃ (metal temperature). curing is also possible at 140℃, with very good mechanical properties and a high gloss surface finish comparable to CASA MID 710 and DY HARD OTB Products, it has high cost performance.
packaging
Net weight: 25kg, polyethylene lining, carton packaging.
shelf life
Please store in a cool, dry place. It is recommended to use up within 12 months.
Emergency Response
Avoid contact with skin and eyes. In case of contact, rinse with plenty of water.
contact
Manager zhang, +8613583101557 (we chat ID: same)
Typical formula
The following is a typical extruded epoxy powder coating formulation. Test results and performance may vary depending on the resin, fillers, and additives used.
The results show that to achieve the best mechanical properties, the curing temperature should not be lower than 140℃. At 200℃,
the coating begins to yellow. The optimal curing temperature is about 160℃, which has the best gloss, mechanical properties, color and gloss properties.
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Epoxy resin GT 7004 (EEW=733)
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60%
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OTB
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3.5%
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Additives *
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36.5%
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Total
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100%
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Curing conditions
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140 ℃ /15min
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160 ℃ /15min
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180 ℃ /15min
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Thickness [mm]
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65
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65
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65
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Glossiness (60 ℃ ) %
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104
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102
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100
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Lightness [L*]
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90
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88
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91
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Yellow [b*]
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-0.5
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-1.2
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-0.8
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Erichsen cupping [mm]
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3
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>8
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>8
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Ball impact test [J]
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8
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>20
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>20
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Conical mandrel bending test[mm]
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20
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<5
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<5
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Cross-cut test
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0-1
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0-1
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0-1
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Epoxy resin GT 7004:
Huntsman Araldite (EEW=805g/ mol)= 4% Benzoin = 0.3%
Titanium dioxide 2160:10.2%
Ultrafine calcium carbonate Omyacarb SV1: =22%
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