In adhesives, tall oil fatty acid (TOFA) is used as a reactive raw material that modifies the binder resin: it esterifies into the chain, wets the filler and supports adhesion in sealant and filler systems. Adhesive and filler systems are listed in the application data of both TOFA 185 and TOFA 180.
Where does TOFA enter an adhesive?
Adhesive formulators usually associate tall oil fatty acid with a single route: dimer acid leading to polyamide hot melt adhesives. The product data shows a wider picture. Adhesive and filler systems are listed directly as an application for both TOFA 185 and TOFA 180, and adhesive systems appears separately among the production areas of TOFA 185.
The reason is the two-ended structure of a fatty acid. The carboxyl end offers a reactive handle for esterification, saponification and interaction with metal surfaces; the unsaturated C18 chain brings flexibility, oxidative crosslinking capability and compatibility with organic phases. In an adhesive system those two properties are useful in different places.
- As the fatty acid component in binder resin synthesis (esterification).
- In filler and pigment wetting, to keep highly filled systems processable.
- In sealant, putty and filler formulations, as a flexibility and surface wetting contributor.
- As a raw material component for adhesion promotion on metal substrates.
- As a separate chemical route through dimer acid to polyamide resin.
How do fatty-acid-modified binder resins work?
A large share of adhesive binders is built on a polyester, alkyd or oil-modified polymer backbone. In those syntheses the fatty acid reacts alongside the polyol and the polyacid, leaving an unsaturated tail pendant on the chain. That tail gives the resin an internal plasticising effect that lowers the glass transition temperature, plus the ability to crosslink oxidatively with air. The result is a binder that is not brittle and tolerates substrate movement.
TOFA is preferred over a vegetable oil in these syntheses because it enters the process as a free fatty acid. The acid value is min 185 for TOFA 185 (ASTM D1980) and min 180 for TOFA 180 (ASTM D1980), so esterification stoichiometry can be calculated directly from it. The level of unsaturation is held by an iodine value of min 150 on both grades (ASTM D5768); that limit is what keeps reactivity constant lot to lot in systems relying on oxidative cure.
BİO BAZLI ÜRÜNLERTall Oil Fatty Acids 185 (TOFA)TOFA 185 is listed with an adhesive and filler systems application and an adhesive systems production area in the product data. Request a free sample for your resin synthesis trial.Its relationship with tackifier resin: complementary, not competing
In an adhesive formulation the job of a tackifier resin is to shift the polymer's glass transition temperature and viscoelastic behaviour so that wet tack increases. A tackifier blends in physically and does not react. Tall oil fatty acid, by contrast, is a reactive raw material that bonds chemically. The two can coexist in the same formulation and do not substitute for one another.
In practice this distinction simplifies the choice. If you are concerned with tack, softening point and the compatibility window, your question is a tackifier resin question and you should read the hydrocarbon resin adhesive guide on this site. If you are building the binder resin itself, looking for an unsaturated fatty acid chain for flexibility and adhesion, or trying to wet a highly filled sealant, your question is a fatty acid question.
Sealants, putties and highly filled systems
Filled adhesives, sealants and putties contain a high proportion of inorganic filler. The core difficulty is wetting the filler particle inside the organic phase and keeping the mix processable. Unwetted filler causes viscosity spikes, difficulty controlling bead thickness and an irregular bond line. The polar carboxyl end of the fatty acid orients to the filler surface while the hydrocarbon tail extends into the organic phase; this is the adhesive equivalent of dispersion chemistry.
The same mechanism works on the adhesion side. The carboxyl group of a fatty acid can interact with metal oxide surfaces, which is why fatty acid derivatives are evaluated as adhesion-promoting components in filler and sealant systems working with metal substrates. The unsaponifiables limit matters here: this is the fraction that does not react and can leave a weak layer at the interface. The limit is max 4% for TOFA 185 (ASTM D1065) and max 6% for TOFA 180.
The dimer acid route: where is it covered?
The best-known adhesive use of tall oil fatty acid is dimerisation of two unsaturated fatty acid molecules into dimer acid, which is then reacted with polyamines into polyamide resin and from there into hot melt adhesives. That route, including its chemistry and its relationship with the iodine value, is covered in a separate article on this site and is not repeated here. This article is about the direct formulation uses that sit outside the dimer acid route.
Which grade for an adhesive?
Both grades carry an adhesive and filler application; the choice is set by the colour tolerance and impurity sensitivity of the finished product. If colour is not critical and the system is a dark, highly filled sealant, TOFA 180 is sufficient. If you are synthesising a light-coloured binder resin and need a tighter specification with a low non-reacting fraction, specify TOFA 185.
Supply, storage and verification
TOFA 185 ships as bulk liquid in 20-22 MT net ISO tank containers and TOFA 180 in 20-24 MT net ISO tank containers; both travel in carbon steel or stainless steel tanks. Storage is 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).
- Verification: acid value (ASTM D1980), iodine value (ASTM D5768), rosin acid (ASTM D1240), unsaponifiables (ASTM D1065).
- KKDIK registered; Turkish Safety Data Sheet (SDS/GBF) provided.
- Certificate of analysis (CoA) for every lot.
- Free sample for laboratory validation.
Does TOFA replace a tackifier resin in an adhesive?
No. A tackifier resin is a non-reacting component that blends in physically and tunes tack and viscoelastic behaviour. TOFA is a reactive fatty acid raw material that bonds chemically into the binder through esterification. They do different jobs in the same formulation.
Which grade is used in sealant and filler systems?
Both grades list adhesive and filler applications. For dark, highly filled sealants TOFA 180 (rosin acid max 3%, unsaponifiables max 6%) is usually sufficient. For light-coloured binder synthesis and work needing a tighter specification, TOFA 185 (max 2% and max 4%) is preferred.
Why does the unsaponifiables limit affect adhesion?
Unsaponifiables are the fraction that does not take part in esterification or saponification and can remain as an unreacted residue at the interface. A lower limit (max 4% on TOFA 185, max 6% on TOFA 180) caps the share of non-reacting components.
Is dimer acid and polyamide hot melt covered here?
No. How dimer acid is produced, its relationship with the iodine value and its conversion into polyamide resin are the subject of a separate article on this site. This article covers the direct adhesive and filler uses outside the dimer acid route.
How do I get a sample and a quote?
State your system type (binder resin synthesis, sealant, filled adhesive), estimated annual volume and destination in the inquiry form on the product page. KORKİMYA provides a free sample and a per-lot certificate of analysis (CoA).