What Are the Classifications of Polyamide Resins?

Polyamide resin is also known as PA resin. Based on their chemical properties and solubility, polyamide resins are generally classified in various ways. Today, we will provide you with a brief overview of this subject.

Dimension 1: Classification by Chemical Properties

Based on their properties, they can be broadly classified into two categories: non-reactive (or neutral) polyamide resins and reactive polyamide resins.

Non-reactive (or neutral) polyamide resins

iSuoChem currently offers neutral polyamide resins as our primary product. These resins are mainly export to customers who manufacture plastic inks. They are produced using dimer fatty acids as the key monomer. Through various modification processes, we are able to create resin products with a range of performance characteristics.

Neutral polyamide resins are mainly used in inks, heat-sealable adhesives, and coatings. They show excellent bonding power to substrates such as polyethylene (PE) and polypropylene (PP), which makes them ideal for printing on plastic films. Inks formulated with these resins offer high gloss, strong adhesion, excellent alcohol dilutability, low gelling tendency, rapid drying, and minimal odor.

Reactive polyamide resins

Reactive polyamide resins are used to cure epoxy resins. They are used in a variety of applications, including thermosetting surface coatings, adhesives, and lining materials. They are also suitable for potting, casting, and hot-melt adhesives.

Dimension 2: Classification by Solubility

1. Benzene-soluble polyamide resins

2. Alcohol-soluble polyamide resins

3. Ester-soluble polyamide resins

Some of our clients—particularly those just entering the polyamide resin industry—often struggle to understand why there are these two distinct classification methods.  Let's consider an alternative perspective:

1. Non-reactive polyamide resins and reactive polyamide resins describes "how the resin works?"—specifically, whether it cures via physical drying or chemical cross-linking.

2. The categories of benzene-soluble, alcohol-soluble, and ester-soluble describe *which solvents* can be used to formulate the resin—a factor that determines its compatibility with specific processing workflows during both manufacturing and application.

These two dimensions can be combined in various ways. For instance, a non-reactive polyamide resin might be alcohol-soluble, making it suitable for use in eco-friendly plastic inks; conversely, another non-reactive polyamide resin might be benzene-soluble, designed for use in traditional formulation systems. Similarly, reactive polyamide resins are also available in various solvent types to meet the diverse processing requirements of different epoxy-based systems.