MB31 · Hardener
Product No. 101 P 203 · Epoxy resin hardener with cyclic amidine structure.
1. Product Information
2. Description
Hardener MB31 is an epoxy resin hardener having the chemical structure of a cyclic amidine. The product is supplied in the form of yellowish flakes.
3. Technical Data
| Property | Value | Unit | Test Method |
|---|---|---|---|
| Nitrogen content | 18.9 – 19.4 | % by wt | Dumas |
| Solidification Point | 90 – 110 | ℃ | ASTM D1015 |
| Appearance | Crystal or Powder in light yellow | ||
| Purity | ≥ 99% | ||
4. Application
- Hardener for highly reactive epoxy resin powder coatings.
- Accelerator for dicyandiamide and epoxy polyester powder coatings.
- Hardener for modifying surface gloss.
Typical Formulations
The following gives the formulations of MB31 for epoxy coatings (parts by weight):
| Component | Formulation I | Formulation II |
|---|---|---|
| Hardener MB31 | 5.8 | 6.7 |
| Epoxy Resin A | 94.2 | — |
| Epoxy Resin B | — | 93.3 |
To obtain desired reactivity, part of the dicyandiamide may be replaced by Hardener MB31.
Mixed polymer powder systems are markedly accelerated with quantities of 0.2 – 1.0% by wt Hardener MB31 (referred to binder). Gloss levels of pure epoxy powder coatings can be varied by partially replacing "Matt Hardener" MB55 or "Matt Hardener" MB68 by "gloss hardener" MB31.
5. Application of Powder Coatings Containing Hardener MB31
The high reactivity of these powders gives rise to low curing temperatures (from 140℃) at relatively short curing times which are of particular interest for use in area of temperature sensitive materials (pigments in the powder; substrates with soldered parts).
The advantage of the highly reactive Hardener MB31 powder coating shows itself in the shortness of the curing times (< 30 sec) or the high curing temperatures (max. 240℃), e.g. in the coating of pipes, fittings, glass and ceramic articles.
This epoxy powder system is characterized by optimal (powder) coating technology related properties and very good adhesion on the most diverse substrates.
6. Storage and Packaging
The product is delivered in flat PE-bags, net weight 20kg or 25kg. If kept cool (0-40℃) and dry in closed bags the product can be stored for at least 1 year in accordance to the specification. All opened bags should be carefully resealed immediately after use.
7. Disclaimer
This information and all further technical advice is based on our present knowledge and experience. However, it implies no liability or other legal responsibility on our part, including with regard to existing third-part intellectual property rights, especially patent rights. In particular, no warranty, whether express or implied, or guarantee of product properties in the legal sense is intended or implied. We reserve the right to make any changes according to technological progress or further developments.
The customer is not released from the obligation to conduct careful inspection and testing of incoming goods. Performance of the product described herein should be verified by testing, which should be carried out only by qualified experts in the sole responsibility of a customer. Reference to trade names used by other companies is neither a recommendation, nor does it imply that similar products could not be used.
Key Facts
MB31 is a low-temperature, fast-curing hardener for epoxy resin powder coatings, manufactured by Huangshan Deping Chemical Co., Ltd. Its chemical name is 2-phenyl-2-imidazoline (4,5-dihydro-2-phenyl-1H-imidazole), a cyclic amidine; its CAS number is 936-49-2, its EINECS number is 213-313-4, and its molecular formula is C9H10N2. MB31 is supplied as light yellow crystals or powder with a purity of at least 99%, a nitrogen content of 18.9-19.4% (Dumas method), and a solidification point of 90-110 °C.
As a hardener, MB31 is used at 5.8-6.7 parts per about 94 parts of epoxy resin in the reference formulations on this page. As an accelerator for dicyandiamide and epoxy-polyester systems, 0.2-1.0% by weight (referred to binder) markedly accelerates curing. MB31 systems cure from 140 °C and can cure in under 30 seconds at high temperatures (up to 240 °C), which suits temperature-sensitive substrates. MB31 is supplied in 20 kg or 25 kg PE bags and can be stored for at least 1 year at 0-40 °C in closed, dry bags.
Frequently Asked Questions
What is MB31 used for?
MB31 (2-phenyl-2-imidazoline, CAS 936-49-2) is a hardener for highly reactive epoxy powder coatings, an accelerator for dicyandiamide and epoxy-polyester powder coatings, and a hardener for adjusting surface gloss.
How much MB31 should be used?
As the sole hardener, the reference formulations on this page use 5.8-6.7 parts of MB31 per about 94 parts of epoxy resin. As an accelerator, 0.2-1.0% by weight referred to binder is used; part of the dicyandiamide may be replaced by MB31 to obtain the desired reactivity.
What is the lowest curing temperature of MB31 systems?
Powder coatings containing MB31 cure from 140 °C at relatively short curing times, and can cure in under 30 seconds at high curing temperatures (maximum 240 °C), for example for pipes, fittings, glass and ceramic articles.
Can MB31 adjust the gloss of a coating?
Yes. Gloss levels of pure epoxy powder coatings can be varied by partially replacing the matt hardeners MB55 or MB68 with MB31, which acts as a gloss hardener in such combinations.
How should MB31 be stored, and what is its shelf life?
MB31 is delivered in flat PE bags of 20 kg or 25 kg. Stored cool (0-40 °C) and dry in closed bags, it keeps for at least 1 year. Opened bags should be resealed immediately after use.