Unveiling the 'Super Accelerator' of the Coatings Industry - The Magical Journey of Acid Catalysts!

Have you ever stopped by those shining cars, or touched the surfaces of those long-lasting furniture, secretly curious about what secret weapons are hidden behind these magical paints? Today, let's delve into the extraordinary world of acid catalysts, the "super accelerator" in amino resin coatings!

The mystery of amino baking paint

Amino baking paint, a representative of high-performance coatings, is ingeniously combined with hydroxyl resin and amino resin. Hydroxyl resins include acrylic resins, alkyd resins, and polyester resins. Amino resins include methyl ether or butyl ether melamine formaldehyde resins, benzyl amino resins, or urea formaldehyde resins.

Imagine that amino baking paint is like a joyful gathering of two good friends - hydroxyl resin and amino resin. But to make this gathering more lively and long-lasting, we need to invite a 'super accelerator' - acid catalyst. It's like a DJ at a party, making the pace of chemical reactions faster and taking the performance of coatings to the next level!

By adding appropriate acid catalysts, the cross-linking between amino resins and hydroxyl containing resins can be accelerated, the baking temperature can be reduced or the curing time can be shortened, the production efficiency can be improved, and the production cost can be reduced; Simultaneously improve the hardness and gloss of the coating, enhance the mechanical properties, water resistance, corrosion resistance, and other properties of the coating.

Acid catalyst type

The 'star family' of acid catalysts 🎨 Classified by active substances, the acid catalyst family shines brightly, with each member having their own characteristics and responsibilities.

Dinnonyl naphthalene sulfonic acid (DNNSA and DNNDSA) is known for its strong catalytic ability and has become the preferred choice for rapid curing reactions; Dodecylbenzenesulfonic acid (DDBSA) has won the favor of many coatings due to its mild and long-lasting properties; And p-TSA, with its outstanding performance in improving glossiness and curing speed, has become a star member in high-end coatings. In addition, phosphoric acid derivatives (AAP) and others also emit light and heat in specific fields due to their unique properties.

🔍  The Wisdom Light of "Closed" Technology 🔍 According to whether the functional group is blocked, catalysts can also be classified into blocked acid catalysts and unblocked acid catalysts.

Some acid catalysts use "closed" technology. This technology is like putting a protective film on the catalyst, keeping it stable during storage and reducing reactions with the surrounding environment. Once suitable conditions are met, this protective film will peel off, releasing the activity of the catalyst and bringing efficient catalytic effect to the coating. This design not only extends the storage life of the coating, but also improves its stability and reliability in use.

Characteristics of acid catalysts

The basic active substance is an organic sulfonic acid or phosphoric acid derivative, hence it is called an acid catalyst.

01 Organic sulfonic acid is known for its strong acidity, which can catalyze curing reactions from room temperature, significantly improving curing speed and reducing curing temperature. However, attention should be paid to its impact on the storage stability of coatings. 02 phosphoric acid derivatives, as representatives of weak acids, are more suitable for compounding with high imino amino resins to achieve mild and effective catalytic effects. 03 Closed type catalysts are treated with organic amines or polymers for sealing, and the acid catalyst after sealing is called a closed type acid catalyst. By sealing and delaying the catalytic reaction to above 65 ℃, the stability of storage in the tank is ensured while reducing adverse reactions with pigments.

Tips for catalytic strength: Different aromatic groups affect the catalytic strength of sulfonic acids in the following relative order of catalytic strength: p-TSA>DNNDSA>DDBSA>DNNSA

The infinite possibilities of application scenarios

From ordinary industrial coatings to automotive paints, from electrostatic spraying to wood coatings, acid catalysts have demonstrated their indispensable importance with their wide range of applications. Whether it's coil printing iron coatings, coil aluminum coatings, electrophoretic paints, can hear coatings, or even paper paints and inks, the presence of acid catalysts can be seen.

Practical Guide: Catalyst Dosage and Selection

1. Usage control

Dosage of closed acid catalyst at different temperatures

Note: 1) Curing for 30 minutes, 75/25 resin/HMMM, acid catalyst activity content 25% 2) For the same catalyst, the higher the curing temperature, the higher the activity content, and the smaller the dosage.

Dosage of unsealed acid catalyst at different temperatures

Note: Curing for 30 minutes, 75/25 resin/HMMM, acid catalyst activity content 25%.

2. Product model and purpose matching

The DNNDSA series (such as LA SC 3155) has superior water resistance, salt spray resistance, and washing resistance, making it an ideal choice for a variety of high-end coatings.

DNNSA series (such as LA SC 3051): Especially suitable for building materials board primer, emphasizing water resistance, corrosion resistance, and flexibility.

The DDBSA series (such as LA SC 3076) is the preferred choice for packaging coatings and automotive coatings, known for its excellent solubility.

The p-TSA series (such as LA SC 3040) is the perfect choice for pursuing high glossiness and low-temperature rapid curing.

AAP series (such as LA SC 3296): Low activity design, customized for curing high activity amino resins (such as high HN/polymeric melamine and phenolic resins), to avoid sharing with alkaline pigments.

Select acid catalyst based on coating performance

Note: ▲ - Highly recommended; ■ - Recommended

When choosing acid catalysts, we need to carefully consider them like selecting partners. Different coating formulations and performance requirements correspond to different types of catalysts. For example, if you pursue high glossiness and fast curing effect, p-TSA will be your best choice; If you value the water resistance and corrosion resistance of coatings more, DNNDSA may become your reliable assistant. Remember this' golden rule ': choose the right catalyst to take your coating performance to the next level!