TOFA 185 (Tall Oil Fatty Acids 185) is a high-purity tall oil fatty acid obtained by distilling crude tall oil, a by-product of cellulose (pulp) production; with a min. acid value of 185 mg KOH/g, max. 2% rosin acid, max. 4% unsaponifiables and a light yellow–amber color, it is a bio-based, oleic/linoleic-rich feedstock preferred for color-sensitive alkyd resins, inks and dimer acid derivatives.

What is TOFA 185?

TOFA stands for Tall Oil Fatty Acids. Tall oil is a by-product of the kraft (sulfate) pulping process used to process wood; fractional distillation of crude tall oil separates fatty acids, rosin acids and unsaponifiable components. TOFA 185 is the fatty-acid-rich, rosin-lean top fraction of this separation.

Chemically, TOFA 185 consists mainly of unsaturated C18 fatty acids (oleic and linoleic acid). The min. iodine value of 150 indicates the density of double bonds in the molecule; this unsaturation is essential for the oxidative air-drying of alkyd resins and for the dimerization reaction in dimer acid production. The number "185" denotes the minimum acid value (mg KOH/g), a measure of free carboxylic acid content.

Typical specification of TOFA 185

  • Appearance: light yellow–amber liquid (low color = high refinement).
  • Acid value: min. 185 mg KOH/g.
  • Iodine value: min. 150 (high unsaturation).
  • Rosin acid: max. 2%.
  • Unsaponifiable matter: max. 4%.
BİO BAZLI ÜRÜNLERTall Oil Fatty Acids 185 (TOFA)TOFA 185 in the KORKİMYA portfolio is offered as a high-purity grade for alkyd resin, ink and dimer acid manufacturers.

How is it used in alkyd resin production?

Alkyd resins are binders produced by the polyesterification of a polyfunctional alcohol (glycerol, pentaerythritol), a polyfunctional acid/anhydride (phthalic anhydride) and a fatty acid. TOFA 185 supplies the "fatty acid" component in this reaction: its carboxyl group esterifies with the polyol and anhydride to bind into the resin backbone, while the unsaturated fatty acid chain gives the resin flexibility and the ability to oxidatively air-dry.

The advantage of using TOFA instead of a classic vegetable oil (soybean, linseed) is that it enters the process directly as a free fatty acid; its high and consistent acid value makes esterification more controlled and reproducible. TOFA-based alkyds are commonly used as binders in architectural and industrial paints, varnishes and printing inks.

Why do high purity and low color matter?

In an alkyd resin, the color and clarity of the finished product depend directly on the purity of the raw material. TOFA 185's low rosin acid content (max. 2%) and light yellow–amber color are critical for two reasons: first, rosin acids cause yellowing and color shift during the reaction; second, low unsaponifiable matter (max. 4%) reduces resin haze and the amount of unreacted residue.

  • A low starting color is essential for color-sensitive white/pastel paints and clear varnishes.
  • Low rosin acid means fewer side reactions during esterification and more stable resin viscosity.
  • A high, consistent acid value allows precise stoichiometry in the resin recipe.
  • Low unsaponifiable matter means less volatile/residue in the final film and better film integrity.

Safe handling and storage

TOFA 185 is a non-flammable but fatty-acid-type liquid; it can cause irritation on skin and eye contact, and heating it to high temperatures can generate fatty acid vapor/fumes. Use chemical-resistant gloves and eye protection, provide ventilation during heated transfers, and follow the product's current Safety Data Sheet (SDS).
  • Store at 20–40 °C in closed containers, protected from direct sunlight and moisture.
  • As an unsaturated fatty acid, prolonged air exposure can cause oxidation/color darkening; keep containers tightly closed.
  • Bulk shipment is in carbon steel or stainless steel tanks; ISO tank 20–22 MT net.
  • Shelf life is typically 12 months and can be extended to 24 months with controlled monitoring.
What does TOFA 185 stand for?

TOFA stands for Tall Oil Fatty Acids. The "185" denotes the product's minimum acid value (min. 185 mg KOH/g).

What raw material is TOFA 185 made from?

It is obtained by fractional distillation of crude tall oil, a by-product of kraft (sulfate) pulp production, making it a renewable, bio-based raw material.

What does TOFA 185 replace in an alkyd resin?

It is used in place of classic vegetable oils (soybean, linseed) as a free fatty acid; its high and consistent acid value makes esterification more controlled and reproducible.

Why is low color important in TOFA 185?

Its light yellow–amber color and max. 2% rosin acid minimize yellowing and color shift in color-sensitive white/pastel paints and clear varnishes.

What does the iodine value of TOFA 185 mean?

The iodine value measures the density of double bonds (unsaturation) in the fatty acid. A min. value of 150 guarantees enough unsaturation for the oxidative drying of alkyd resins and for dimerization in dimer acid production.