Binder for Water-based Ink

What ink binders can be used for water-based inks? - Binder for water-based ink

Binders used for water-based inks are very different from those used for solvent-based inks. Since the resin in water-based ink is dissolved and diluted with water, the resin(As a kind of binder) for water-based ink has to be water-soluble. This means that the resin used in the water-based ink binder is limited to the range of water-soluble resins. 

There are three main types of binders for water-based inks: water-soluble, alkali-soluble, and diffusive. Some of the most commonly used binders are rosin-modified maleic acid resin, water-soluble acrylic resin, styrene-modified maleic acid resin, polyimide resin, shellac, and tyrane.

1. Water-Soluble Binders

Some water-soluble binders include polyvinyl alcohol(PVA Resin), hydroxyethyl cellulose(HEC), and polyvinylpyrrolidone(PVP). These binders can be dissolved in water without any issues. So, there are some limits to how you can use inks made with these binders. Only applicable when the ink film is soluble in water or does not come into contact with water.

Polyvinyl alcohol resin

2. Alkali-soluble binder

The ink must have a certain viscosity in order to be transferred from the ink roller to the printing plate, and then from the printing plate to the printing material. The main way to adjust the viscosity of water-based inks is by changing the amount of water. After the ink is transferred to the printing material and dried into an ink film, it is usually required that the ink film is insoluble in water. For example, the ink on commercial bags should not get soaked or melted by rain. Or the shopping bags should not be damaged by being placed in a humid area. This means that the binder in water-based inks must be water-soluble during the printing process, but must become water-insoluble once the print is dry.

Alkali-soluble binders can meet all of the above requirements. An alkali-soluble binder is basically an alkaline solution of acid resin, which is a water-soluble salt similar to soap. The resin in the alkali-soluble binder is an acidic resin. Add the right amount of ammonia to make a soluble resin salt after the chemical reaction between the two. As the ink dries, the ammonia evaporates, making the ink insoluble in water. How well this type of ink works depends on the acid resin used. Many carboxylated or acid-containing resins can be used for alkali-soluble binders. Some of them can provide hardness, abrasion resistance, and heat resistance similar to alcohol solvent resins.

3.Diffusion binder

Diffusing binders are basically fine resin particles suspended in water. If the resin particles are less than 1 pm, it's called a colloidal suspension. If they're 1 pm or larger, it's an emulsion or suspension. 

Latex is a binder used in water-based latex paints, whether they have a colloidal suspension or an emulsion. These binders usually contain polymers of propylene, ethylene, or styrene-butadiene. Latex is created when monomers (or small molecules) interact in water. Emulsifiers like amine salts can be used to make stable suspensions of small particles. Once the paint has dried, the particles in the latex come together to form a film. 

There are a lot more advantages to latex than there are to dissolved resins. 

A. Latex can be dense and low in viscosity. This makes it great for producing high-quality thin coatings.

B. Latex can also contain relatively large polymer molecules. Generally speaking, these molecules are usually harder than small molecules, are resistant to abrasion and heat, and have good adhesion. Human molecules usually make the solution too thick, but this doesn't happen with latex. This is what makes latex ink so special. Since low-denier latex becomes insoluble when it solidifies, latex inks are difficult to print with and to clean. Latex ink is better suited as a coating ink.

Latex can also be mixed with alkali soluble binders. This necessarily means that it can both retain some of its unique properties and print like an alkali soluble binder.

At present, acrylic resin is widely used as binder(adhesives) abroad.

iSuoChem acrylic resin: including water-based acrylic resin, water-based acrylic emulsion, and thermoplastic acrylic resin.

Features: Acrylic resin has great advantages in gloss, weather resistance, water resistance, chemical resistance, and pollution resistance. In addition, it works very well in dispersing, dissolving, and synthesizing molecular latex.

Many years ago, the quality of domestic acrylic resin and polymer latex was not good enough, and there were some unstable factors. However, considering the cost of imported acrylic resin and latex, and the long delivery time, it brought troubles to ink factories.

Water based acrylic resin and acrylic emulsion in 40 container

Therefore, in recent years, iSuoChem has been developing more economical and stable quality acrylic resin and acrylic emulsion. The products currently sold to countries around the world have received the favor of many new and old customers.