In printing inks, tall oil fatty acid (TOFA) supplies the carboxyl group that wets and disperses the pigment, and the fatty acid component of alkyd-based binders. For colour-sensitive inks, specify TOFA 185 with a rosin acid content of max 2%; the TOFA 180 limit is max 3%.
What does a fatty acid do in a printing ink?
At its simplest a printing ink has three parts: the pigment that gives colour, the vehicle (binder system) that carries the pigment and anchors it to the substrate, and the additives that tune flow behaviour. Tall oil fatty acid enters this structure at two separate points. First, as a free fatty acid it takes part directly in pigment wetting and dispersion chemistry. Second, it forms the fatty acid leg of the alkyd and oil-modified polymers used as ink binders.
This dual role is visible in the TOFA 185 product data: printing ink and pigment dispersion sits alongside alkyd resin and oil-modified polymer production among the same grade's production areas. The practical consequence for an ink maker is that one raw material feeds both the dispersion side and the binder side of the formulation.
Pigment wetting and dispersion: what the carboxyl group does
Pigment enters the ink as a dry powder and its natural tendency is to re-agglomerate. The job of dispersion is to break the pigment aggregates apart and keep the separated particles stable in the vehicle. The polar carboxyl end of the fatty acid orients towards the pigment surface while the unsaturated C18 hydrocarbon tail extends into the vehicle phase; this two-ended structure is the basis of wetting and stabilisation.
- Wetting: the carboxyl group displaces air and moisture from the pigment surface so the vehicle can contact the particle.
- Milling efficiency: a well-wetted pigment reaches the target fineness in fewer passes on a three-roll or bead mill.
- Resistance to re-agglomeration: the adsorbed fatty acid layer creates a steric barrier between particles.
- Colour strength and gloss: a well-dispersed pigment delivers more colour strength at the same pigment loading.
- Rheology: dispersion quality directly affects how the ink flows and transfers.
The measure of carboxyl group density is the acid value. TOFA 185 runs an acid value of min 185 (ASTM D1980) and TOFA 180 min 180 (ASTM D1980). Holding free fatty acid content above those limits lot to lot is what keeps a dispersion recipe behaving the same way on every batch.
BİO BAZLI ÜRÜNLERTall Oil Fatty Acids 185 (TOFA)TOFA 185 in the KORKİMYA portfolio lists printing ink and pigment dispersion among its production areas. Request a free sample to run your own milling trial.TOFA in alkyd-based ink binders
In sheetfed offset, web offset and some packaging inks the backbone of the binder is an alkyd or oil-modified polymer. In that polymer the fatty acid esterifies with a polyol and an anhydride to attach to the chain, while the unsaturated chain carries the ink's oxidative drying behaviour. Because TOFA enters the process as a free fatty acid, esterification stoichiometry can be calculated more precisely than when a vegetable oil is used.
The level of unsaturation is tracked by the iodine value: both grades run min 150 (ASTM D5768). That is the specification limit that keeps reactivity predictable from lot to lot in binder systems relying on drying and oxidative crosslinking.
Fatty acid or hydrocarbon resin? Two different components in the same ink
In an ink formulation, tall oil fatty acid and hydrocarbon resin are not alternatives to each other; they do different jobs. The fatty acid is a reactive raw material that sits at the pigment interface and in the binder backbone. The hydrocarbon resin is a non-reacting modifying resin that tunes the vehicle's viscosity, tack and gloss. A reader looking for hydrocarbon resin selection, Gardner colour and softening point in ink should read the hydrocarbon resin ink guide on this site; this article covers only the fatty acid side.
Colour and rosin acid: why TOFA 185 for ink?
In ink, colour starts with the raw material. Rosin acids are the abietic-type acids left after crude tall oil distillation, and they influence colour development and viscosity behaviour. That is why, on colour-sensitive work, the decisive specification is not the acid value but the rosin acid limit.
TOFA 185 caps rosin acid content at max 2% (ASTM D1240) and unsaponifiables at max 4% (ASTM D1065), and is supplied as a light yellow to amber liquid. TOFA 180 allows rosin acid max 3% and unsaponifiables max 6%, and is an amber to dark amber liquid. Where light shades, white and pastel blends or large solid areas cannot tolerate a colour shift, specify TOFA 185.
How do you verify lot-to-lot consistency?
In ink production the cost of a raw material shift is re-milling and lost colour matching. Verification therefore runs on four numbers on the incoming material, all of which appear on the per-lot certificate of analysis (CoA).
- Acid value (ASTM D1980): free fatty acid content, the basis of dispersion and esterification behaviour.
- Iodine value (ASTM D5768): unsaturation, hence drying and oxidative crosslinking reactivity.
- Rosin acid content (ASTM D1240): colour and viscosity behaviour.
- Unsaponifiables (ASTM D1065): the non-reacting fraction that can cause haze.
KORKİMYA provides a certificate of analysis (CoA) for every lot and a free sample for laboratory validation. That is the fastest way to run a milling trial with your own pigment system before committing the ink line.
Supply, storage and documentation
TOFA 185 ships as bulk liquid in 20-22 MT net ISO tank containers, in carbon steel or stainless steel tanks. For TOFA 180 the ISO tank container capacity is 20-24 MT net. Both grades are stored in closed containers between 20-40°C, away from direct sunlight; shelf life is 12 months and can be extended to 24 months with quality monitoring.
- CAS number: 61790-12-3 (both grades).
- Storage: 20-40°C, closed container; preferred tank material carbon or stainless steel.
- Shelf life: 12 months, extendable to 24 months with quality monitoring.
- KKDIK registered; Turkish Safety Data Sheet (SDS/GBF) provided.
- Certificate of analysis (CoA) for every lot.
TOFA 185 or TOFA 180 for printing ink?
TOFA 185 for colour-sensitive inks. It is the tighter, lighter grade with rosin acid max 2% and unsaponifiables max 4%, supplied as a light yellow to amber liquid. TOFA 180 allows rosin acid max 3% and unsaponifiables max 6%, and printing ink is not listed among its applications in the product data.
Is TOFA sufficient on its own for pigment dispersion?
No. TOFA is a reactive fatty acid raw material that contributes to wetting and stabilisation; a complete ink vehicle also contains a binder polymer, a modifying resin, solvent or oil and rheology additives. The right approach is a sample-based milling trial in your own pigment and vehicle system.
How is it different from hydrocarbon resin in ink?
The fatty acid is a reactive raw material at the pigment interface and in the alkyd binder backbone. Hydrocarbon resin is a non-reacting modifying resin that tunes viscosity, tack and gloss. They do different jobs in the same formulation and do not substitute for one another.
Why does an iodine value of min 150 matter in ink?
The iodine value (ASTM D5768) indicates the degree of unsaturation. A min 150 level keeps reactivity predictable lot to lot in binder systems that rely on oxidative drying and crosslinking.
How do I get a sample and a quote?
State your application (printing ink, pigment dispersion or binder production), estimated annual volume and destination in the inquiry form on the product page. KORKİMYA provides a free sample for laboratory validation and a per-lot CoA.