Types of Amino resins and Their Applications in Coatings

Amino resin is an important type of thermosetting resin, which is formed by the condensation polymerization of amino-containing compounds and aldehydes (mainly formaldehyde). These resins usually need to be modified with alcohols in order to be soluble in organic solvents and have good miscibility and reactivity for application in coating preparation. According to the amino compounds used, amino resins can be divided into three major categories: urea-formaldehyde resin, melamine-formaldehyde resin and benzomelamine resin.

Classification of amino resins

Urea-formaldehyde resin

Urea-formaldehyde resin, also known as urea-formaldehyde resin (UF), is a polymer obtained by the reaction of urea and formaldehyde. During processing and molding, these resins undergo cross-linking reactions to form insoluble and infusible thermosetting resins. After curing, urea-formaldehyde resin is translucent, lighter in color, resistant to weak acids and weak alkali, has excellent insulation properties, very high wear resistance, and is relatively affordable. However, urea-formaldehyde resin is easily affected by strong acids and alkalis, has poor weather resistance, and is not suitable for long-term exposure to harsh environments. This resin is often used to prepare water-soluble resin, which is easy to cure under neutral conditions. The cured resin is non-toxic, colorless, and has good light resistance and thermoforming properties.

Melamine formaldehyde resin

Melamine formaldehyde resin, also called melamine formaldehyde resin (MF), is a polymer produced by the reaction of melamine and formaldehyde. These resins undergo cross-linking reactions during processing and molding to form insoluble and infusible thermosetting resins. After curing, melamine formaldehyde resin is colorless and transparent, has good stability, can remain stable in boiling water, and can even be used at temperatures up to 150 degrees Celsius. It also has self-extinguishing properties, arc resistance and good mechanical properties.

Benzinated melamine resin

Benzinated melamine resin is a resin produced by introducing a phenyl substituent into the melamine molecule. It has similar properties to melamine, being alkaline and adding to formaldehyde. After these resins undergo methyl etherification or butyl etherification treatment, they can be used together with alkyd resins, acrylic resins, etc. as cross-linking agents for thermosetting coatings. Under different processing methods, they can be used in thermosetting coatings, paints and other fields.

Application of amino resin in coating field

Amino resins are widely used in the coating field. They are generally compatible with other resins and can be cross-linked with different types of resins through heat to improve the performance of the coating. Amino resin paint can be used in many applications such as automobiles, steel furniture, household appliances, and metal coatings. The characteristics of these paints include light color, high gloss, high hardness, good electrical insulation, good aging resistance, and fast drying speed, making them very popular in industrial production.

In general, amino resins are a class of versatile thermosetting resins that play an important role in the paint and coating industry. By adjusting different types of amino resins and their ratio with other resins, diversified performance requirements can be achieved to meet the needs of different fields. With the continuous development of science and technology, amino resins and their application fields will continue to expand, providing more innovations and solutions for various industrial applications.