Printing Ink Binders
In printing ink compositions, the purpose of the binder is to adhere components within an ink to the printed surface and allow a film to be formed upon drying. The resins used as the binder in an ink formulation influence performance properties such as the adhesion, appearance, and durability of the ink. Selection of the appropriate binder for an ink formulation is crucial and should be based on the printing process as well as the demands of the end application for the ink.Elvacite® Acrylic Printing Ink Resins
As a binder in flexographic, gravure, and screen-printing inks, Elvacite® Acrylic Resins offer outstanding adhesion to packaging films and foils as well as remarkable resistance to discoloration from heat and UV exposure. Elvacite® Acrylic Resins also form films that create grease, oil, and water resistance, making them an ideal binder for inks applied onto surfaces that come into contact with greasy or wet food materials. Elvacite® Acrylic Resins are highly compatible with many other common binders such as cellulose acetate butyrate, chlorinated rubber, vinyl resins, and rosin derivates. Thus, they can either be used as a main acrylic binder for inks or blended to further adjust performance properties for specific application requirements.
Elvacite® Resins for Flexographic Inks
| Grade | Tg (°C) | Molecular Wt. | Solubility |
|---|---|---|---|
| Elvacite® 2028 | 47 | 59,000 | Alcohols, Ketones, Esters, Glycol Ethers |
| Elvacite® 2042 | 65 | 221,000 | Alcohols, Ketones, Esters, Glycol Ethers |
| Elvacite® 2043 | 66 | 50,000 | Alcohols, Ketones, Esters, Glycol Ethers |
The most common solvents for flexographic inks are rich in alcohol. Thus the binder for a flexographic ink formulation should be soluble and compatible with alcohols. Elvacite® 2028, 2042, and 2043 are all broadly soluble in alcohol and are excellent binders for flexographic inks. Elvacite® 2028 shows outstanding adhesion to foils, polymer-coated films, polystyrene, and cellulosics. In addition, Elvacite® 2028 will not discolor due to UV exposure, making it an ideal ink binder for printed laminated film structures and heat-seal packaging that is exposed to sunlight. Elvacite® 2028 has excellent pigment-wetting properties and may also be blended with a co-binder such as alcohol-soluble butyrate to customize for heat-smear resistance, adhesion, and flexibility. If greater abrasion resistance is required for the application, Elvacite® 2042 and 2043 are recommended.
Elvacite® Resins for Gravure Inks
| Grade | Tg (°C) | Molecular Wt. | Solubility |
|---|---|---|---|
| Elvacite® 2013 | 76 | 34,000 | Ketones, Esters, Glycol Ethers |
| Elvacite® 2614 | 79 | 52,000 | Ketones, Esters, Glycol Ethers |
Lower viscosity binders are preferred for gravure inks. Elvacite® 2013 is a low molecular weight acrylic resin that is recommended for gravure inks that will be printed on packaging films and where resistance to yellowing is required. If odor is a concern, Elvacite® 2614 is specifically recommended as it is a low-odor grade.
Elvacite® Resins for Screen Printing Ink
| Grade | Tg (°C) | Molecular Wt. | Solubility |
|---|---|---|---|
| Elvacite® 2045 | 53 | 193,000 | Hydrocarbons, Ketones, Esters, Glycol Ethers |
| Elvacite® 4067 | 50 | 57,000 | Hydrocarbons, Ketones, Esters, Glycol Ethers |
For screen-printing inks, flexibility and solubility in aliphatic hydrocarbons are important. Elvacite® 2045 is a highly flexible butyl methacrylate resin that is soluble in white spirits and hydrocarbons that are frequently used in screen-printing inks. Alkyd resins are also commonly used in screen-printing ink formulations. Elvacite® 4067 is recommended for use with alkyd systems to improve color stability, reduce dry time, and enhance weatherability.
Summary
When it comes to finding the right binder for ink formulations, there is often an Elvacite® Acrylic Resin grade that provides the right combination of benefits that formulators look for within their specific ink-printing applications. Elvacite® resins offer a wide range of compatibility for solvents, pigments, and co-binders; promote adhesion onto various materials; have excellent weatherability when exposed to UV; and impart grease, oil, and water resistance for printed surfaces.
Given the importance of selecting the proper acrylic binder for your printing ink formulations, if you have questions about Elvacite® Acrylic Resins and which grade will provide the performance qualities you're looking for, ChemPoint is here to help. Various starting point ink formulations using Elvacite® are also available to share. Contact us below to request a quote and speak to a product specialist about Elvacite®.
