PRODUCTS

C36 DIMER ACID

C36 Dimer Acid is mainly used as polyamide resin, epoxy resin modifier and fuel oil, lubricating oil, cutting oil additives.
C36 Dimer Acid serves a crucial role in the oleochemical industry, finding widespread applications across various sectors such as coatings, surfactants, lubricants, printing inks, and hot melt adhesives.

CAS Number: 61788-89-4
EC Number: 500-148-0
MDL Number:MFCD00163478
IUPAC / structural name / canonical name: One IUPAC-style name is 9-[(Z)-non-3-enyl]-10-octylnonadecanedioic acid (a representation of one typical isomer)
Molecular Formula:C36H64O4
Molecular weight (approx): ~ 560.91 g/mol (per

SYNONYMS:
dimerized fatty acids, Dimer Fatty acid, C36 DIMER ACID, C36 Dimer acidC, FATTYACIDS,DIMERACIDS, High purity dimer acid, C18-Unsatd.fattyacidsdimers, Fatty acids, diMeracids, C18, Dimerfettsure, C18, ungesttigt, Fatty acids, C18-unsatd., dimers, (Octadecadienoic acid) dipolymer, Dimer Fatty Acid, C36 Dimer Acid, (Octadecadienoic acid) dipolymer, dimerized fatty acid, C36 Dimer acid C, dibasic acid, C36 dimeric acid, fatty acids, dimer acids, C18 unsaturated dimers, high purity dimer acid, IUPAC: 9-[(Z)-non-3-enyl]-10-octylnonadecanedioic acid, Dimer Fatty acid, Monobasicacid, C36 DIMER ACID, C36 Dimer acidC, Trimericfattyacid, FATTYACIDS,DIMERACIDS, High purity dimer acid, C18-Unsatd.fattyacidsdimers, Fatty acids, diMeracids, C18, Dimerfettsure, C18, ungesttigt, C36 Dimer acid 9-[(3Z)-non-3-en-1-yl]-10-octylnonadecanedioic acid nonadecanedioic acid, 9-[(3Z)-3-nonenyl]-10-octyl- 9-[(3Z)-3-Nonen-1-yl]-10-octylnonadecanedioic acid Nonadecanedioic acid, 9-[(3Z)-3-nonen-1-yl]-10-octyl-, Dibasic Acid, C36 Dimer acid, Unsaturated fatty acids,C18,dimers, Fatty acids,C18-unsatd.,dimers, Fatty acids,dimer acids,C18, UCN 1355, Empol 1014, Empol 10-14, Empol 1003, Haridimer 300, Empol 1020, Empol 1061, C36 dimer acid, Empol 1026, Radiacid 0970, Unidyme 10, Pripol 1012LQ, C18-unsaturated fatty acid dimers, Haridimer 250K, 37317-30-9, 123997-55-7, 872420-55-8, 1450829-02-3, Fatty acids C18-unsatd dimers, (Octadecadienoic acid) dipolymer, Dilinoleic acid, DTXSID70873445, 1572670-81-5, 9-((3Z)-Non-3-en-1-yl)-10-octylnonadecanedioic acid, 9-[(3Z)-non-3-en-1-yl]-10-octylnonadecanedioic acid, RefChem:1074880, DTXCID408062, EC 500-148-0, 9-[(Z)-non-3-enyl]-10-octylnonadecanedioic acid, C36 Dimer acid, SCHEMBL633756, Dimer Acid, C36 Dimer Acid, dilinoleic acid, Dimer Fatty acid, FATTYACIDS,DIMERACIDS, Fatty acids, diMeracids, C18, (Octadecadienoic acid)dipolymer, Fatty acids, C18-unsatd., dimers, (Octadecadienoic acid) dipolymer, Fatty acids, C18 unsaturated dimers, FATTYACIDSUNSATURATEDC18DIMERSDISTILLED, FATTYACIDSUNSATURATEDC18DIMERSNON-DISTILLED, 9-[(3Z)-non-3-en-1-yl]-10-octylnonadecanedioic acid

C36 Dimer Acid is a colorless transparent liquid.
The relative density of C36 Dimer Acid is 0.95, and the flash point is 280-350 °C.
C36 Dimer Acid is soluble in acetone, ethanol, ether and almost all solvents such as aliphatic and naphtha

C36 Dimer Acid, refers to the natural oil linoleic acid as the main component of the straight chain of unsaturated fatty acids or unsaturated fatty acid esters in the white clay catalysis, the dimer is self-polycondensed by a Diels-Alder cycloaddition reaction or the like.
C36 Dimer Acid is a mixture of isomers in which the main components are dimers, small amounts of trimers or multimers and minor amounts of unreacted monomers.

C36 Dimer Acid refers to the dimerization of linear unsaturated fatty acid or unsaturated fatty acid ester with linoleic acid of natural oil as the main component, which is self-condensed through Diels-Alder cycloaddition reaction under the catalysis of clay.
C36 Dimer Acid is a mixture of various isomers, in which the main components are dimers, small amounts of trimers or multimers, and traces of unreacted monomers.

C36 Dimer Acid is an important oleochemical that is widely used in coatings, surfactants, lubricants, printing inks, hot melt adhesives and other industries.
C36 Dimer Acid (dimerized fatty acids) is dicarboxylic acids produced by dimerizing unsaturated fatty acids obtained from tall oil, oleic acid, canola oil or cottonseed oil, usually on clay catalysts.

C36 Dimer Acid has similar reactivity with general fatty acids, can form metal salts with alkali metals, can be derived into acyl chloride, amide, ester, diamine, diisocyanate and other products.
C36 Dimer Acid with long chain alkyl and ring structure, and a variety of solvents have good miscibility, good thermal stability, in winter is not curing, and vapor pressure still has corrosion resistance, good lubrication.

Therefore, C36 Dimer Acid is widely used as an additive for fuel oil, lubricating Chemicalbook oil, calender oil, hydraulic oil, cutting oil, etc.
C36 Dimer Acid (C36H64O4) is a dimerized organic carboxylic acid derivative, specifically a C36 Dimer Acid formed from the polymerization of unsaturated fatty acids.

At room temperature, C36 Dimer Acid typically exists as a viscous, pale yellow to amber-colored liquid or semi-solid with a mild, characteristic fatty acid odor.
C36 Dimer Acid belongs to the class of long-chain dicarboxylic acids and exhibits amphiphilic properties due to the presence of two carboxylic acid functional groups separated by a long aliphatic chain structure.

C36 Dimer Acid was first synthesized in the mid-20th century through the thermal or catalytic dimerization of unsaturated C18 fatty acids such as oleic acid.
The process generally involves heating the monomeric fatty acid under controlled conditions in the presence of a catalyst like clay or acidic ion exchange resins.

This reaction leads to the formation of a cycloaliphatic ring system connecting two fatty acid chains, resulting in a molecule with two terminal carboxylic acid groups.
While primarily produced synthetically, trace amounts may be found in certain natural oils where partial dimerization occurs during extraction or refining processes.

Industrially, C36 Dimer Acid is prepared via the dimerization of distilled tall oil fatty acids under elevated temperatures and pressure, followed by purification through distillation and filtration steps.
C36 Dimer Acid is formed by the controlled dimerization (typically via Diels–Alder / cycloaddition processes) of unsaturated fatty acids (e.g. oleic, linoleic) obtained from natural oils (e.g. tall oil).

C36 Dimer Acid is a dicarboxylic acid with two long hydrocarbon chains linked via a central ring or bridging moiety.
C36 Dimer Acid refers to a dimer acid whose nominal formula corresponds to ~36 carbons in the total dimer skeleton (i.e. two ~C18 chains joined).

C36 Dimer Acid is one of the most common dimer acids in commercial use.
C36 Dimer Acid is often supplied as a mixture / isomeric blend (i.e. the “dimer acid” product is not a single pure isomer) — minor amounts of monomers, trimers, or other oligomers may be present.

C36 Dimer Acid, or dimerized fatty acids, are dicarboxylic acids prepared by dimerizing unsaturated fatty acids obtained from tall oil, usually on clay catalysts.
The CAS number of C36 Dimer Acid is [61788-89-4].

C36 Dimer Acid is a light yellow or yellow viscous transparent liquid.
C36 Dimer Acid usually contains predominantly a dimer of oleic acid.
C36 Dimer Acid is a corresponding material where the resulting molecule consists of three fatty acid molecules.

C36 Dimer Acid's CAS number is [68937-90-6].
C36 Dimer Acids can be converted to dimer amines by reaction with ammonia and subsequent reduction.

USES and APPLICATIONS of C36 DIMER ACID:
C36 Dimer Acid is mainly used as polyamide resin, epoxy resin modifier and fuel oil, lubricating oil, cutting oil additives.
C36 Dimer Acid has similar reactivity with common fatty acids, can be formed with alkali metal metal salts, can be derived into acid chloride, amide, ester, Diamine, diisocyanate and other products.

C36 Dimer Acid with long chain alkane and cyclic structure, and a variety of solvents have good mutual solubility, good thermal stability, in the winter is not cured, and the vapor pressure still has anti-corrosion effect, good lubricity.
Therefore, C36 Dimer Acid is widely used as an additive for fuel oil, lubricating oil, calender oil, hydraulic oil, cutting oil and the like.

The ester of C36 Dimer Acid can be effectively used as a viscosity stabilizer in a wide temperature range; The metal salt of this product is widely used as a thickener for Grease.
The application of the product in the manufacture of polyester resin accounts for 80-90% of the total consumption of C36 Dimer Acid, and the rest is used for oil additives, surfactants, synthetic paints, inks, adhesives, curing agents, etc.

C36 Dimer Acid is mainly used as modifier of polyamide resin, epoxy resin and additive of fuel oil, lubricating oil and cutting oil
C36 Dimer Acid is widely used in the synthesis printed circuit board material, ink manufacturing, rocket motor materials.
High-pure C36 Dimer Acid also can be used for synthesis of high class amilan, material of high class ink, coating and heat melting glue, material surfactant, inhibitor, lubricant, antirust oil.

C36 Dimer Acid is mainly used as a modifier for polyamide resin and epoxy resin and an additive for fuel oil, lubricating oil and cutting oil.
C36 Dimer Acid serves a crucial role in the oleochemical industry, finding widespread applications across various sectors such as coatings, surfactants, lubricants, printing inks, and hot melt adhesives.

C36 Dimer Acid is the result of the dimerization process involving linear unsaturated fatty acids or unsaturated fatty acid esters, primarily utilizing linoleic acid derived from natural oils.
This reaction, which occurs via a Diels-Alder cycloaddition mechanism catalyzed by clay, produces a complex mixture predominantly consisting of dimeric isomers, with minor quantities of trimers or multimers, as well as trace amounts of unreacted monomers.

C36 Dimer Acid and amine will react to produce much different molecular weight polyamide resin.
C36 Dimer Acid is mainly used to make graver or flexo printing ink, epoxy paint, the curing agent and the epoxy cementing material, lubricant.

C36 Dimer Acid is used to make hot melt adhesive, which is widely used to make thermoplastic product and joint of electric cable in the posts and telecommunications, the communication equipment.
Main uses: C36 Dimer Acid and amine can produce various kinds of polyamides with different molecular weight with the participation of different additives (excipients), which are widely used in the manufacture of plastic gravure printing ink.

C36 Dimer Acid reacts with polyamines to form polyamides with active amines, which are widely used in the manufacture of two-component epoxy paint, curing agent and epoxy binder.
The cured products have good mechanical and electrochemical properties.

In addition, C36 Dimer Acid can also be used to manufacture various low-temperature and low-pressure special lubricants and metal processing oils.
C36 Dimer Acid is used in manufacturing hot melt adhesives, and widely used in manufacturing thermoplastic products of electronics and electrical appliances, automotive interiors, shoes, etc.

C36 Dimer Acid is mainly used as polyamide resin, but also used in oil additives, surfactants, synthetic paints, inks, adhesives, curing agents, etc.
C36 Dimer Acid is an important oleochemical that is widely used in coatings, surfactants, lubricants, printing inks, hot melt adhesives and other industries.

C36 Dimer Acid can be used to synthesize polyamide resins and hot melt adhesives.
C36 Dimer Acid is also used in alkyd resins, adhesives, surfactants, fuel oil additives and lubricants.
The ester of C36 Dimer Acid can be used effectively as a viscosity stabilizer over a wide temperature range.

The metal salt of C36 Dimer Acid is widely used as a thickening agent for grease.
The application of C36 Dimer Acid in the manufacture of polyacyl resin accounts for 80-90% of the total consumption of dimeric acid, and the rest is used in oil additives, surfactants, synthetic paints, inks, adhesives, curing agents, etc.

C36 Dimer Acid is mainly used as polyamide resin, epoxy resin modifier and fuel oil, lubricating oil, cutting oil additive.
C36 Dimer Acid finds extensive application in the formulation of polyamide resins, epoxy curing agents, lubricants, and surfactants due to its high molecular weight and bifunctional nature.

C36 Dimer Acid is widely used across several industries due to its fatty acid-derived backbone and multifunctional acid groups.
Some applications and benefits:
Polyamide / Resin / Polymer intermediate: A major use of C36 Dimer Acid is as a comonomer in polyamide resins, hot-melt adhesives, epoxy curing agents, etc.

C36 Dimer Acid imparts flexibility, toughness, improved adhesion, hydrolytic stability.
Adhesives / coatings / inks / paints: C36 Dimer Acid is used in the formulation of adhesives, alkyd resins, printing inks, coatings, etc.
Lubricants / oil additives: C36 Dimer Acid or its esters are used in lubricants, metal-working fluids / additives, for performance improvement at high temperatures, corrosion resistance, etc.

Surfactants / dispersants: C36 Dimer Acid (or their salts / derivatives) are sometimes used in surfactant or dispersant roles within formulations, benefiting from the long hydrophobic chains plus acid functionality.
Specialty / niche / functional materials: Because of their unsaturation, C36 Dimer Acid (or derivatives) may be further chemically modified (e.g. epoxidized) and used in specialty polymers, crosslinked networks, etc.

Furthermore, hydrogenated C36 Dimer Acid variants are used when improved color stability, oxidation resistance, and lower unsaturation are desired.
C36 Dimer Acids are used primarily for synthesis of polyamide resins and polyamide hot melt adhesives.
C36 Dimer Acid is also used in alkyd resins, adhesives, surfactants, as fuel oil additives, lubricants, etc.

-Polyamide Resins uses of C36 Dimer Acid:
C36 Dimer Acid provides flexibility and adhesion in coatings and hot-melt adhesives.
C36 Dimer Acid is used in both reactive polyamides (epoxy curing agents) and non-reactive polyamides.
C36 Dimer Acid enhances toughness and hydrolytic stability.

-Lubricants & Oil Additives uses of C36 Dimer Acid:
C36 Dimer Acid delivers thermal stability and corrosion inhibition.
C36 Dimer Acid functions as performance additive in metalworking fluids.
C36 Dimer Acid improves high-temperature performance.

-Coatings & Adhesives uses of C36 Dimer Acid:
C36 Dimer Acid enhances flexibility and chemical resistance in alkyd resins.
Key component in durable hot-melt adhesives.
C36 Dimer Acid improves weatherability in protective coatings.

-Specialty Applications of C36 Dimer Acid:
Intermediate for specialty surfactant synthesis.
Component in oilfield chemicals.

CHEMICAL PROPERTIES of C36 DIMER ACID:
C36 Dimer Acid is a multifunctional compound, so it can carry out many chemical reactions and has similar reactivity to general unsaturated fatty acids.
C36 Dimer Acid can react with alkali metals to form metal salts, and can also be derived into acid chlorides, amides, esters, diisocyanates and other products.

REACTION MECHANISM of C36 DIMER ACID:
C36 Dimer Acid is obtained by heating and polymerizing unsaturated fatty acid under the action of catalyst.
The reaction mechanism of dimerization, the current consensus view is the theory of Diels-Alder addition reaction between conjugated and non-conjugated unsaturated fatty acids.

PREPARATION of C36 DIMER ACID:
C36 Dimer Acid is prepared by heating and polymerizing unsaturated fatty acid under the action of catalyst.

PRODUCTION of C36 DIMER ACID:
C36 Dimer Acid is produced from different fatty acids by heating.
Necessary are a fatty acid with conjugated double bonds or other unsaturated fatty acids.
Examples of such fatty acids are conjugated linoleic acids.
The reaction is carried out via Diels-Alder addition, whereby a partially unsaturated C6 ring is formed.
Besides the dimer, trimers as well as (unreacted) monomers of the fatty acids may be present in the mixture.

PHYSICAL PROPERTIES of C36 DIMER ACID:
Pure C36 Dimer Acid is a light yellow transparent viscous liquid with good thermal stability: it does not crystallize at a low temperature of-20 °C, and does not lose its transparent fluidity; it does not evaporate or gel at 250 °C.
The color will darken significantly when heated in air.

Exposure to metal ions, especially copper and iron ions, can promote color deterioration.
Hydrogenated C36 Dimer Acid is almost colorless and transparent liquid, and the color is not easy to deepen even when heated.
C36 Dimer Acid is insoluble in water, but soluble in ether, ethanol, acetone, chloroform, benzene, petroleum series solvents.

PHYSICAL AND CHEMICAL PROPERTIES of C36 DIMER ACID:
Colorless transparent liquid.
Relative density 0.95.
Flash point 280-350 deg C.
Soluble in acetone, ethanol, ether and aliphatic, naphtha and other almost all solvents.

CHEMICAL / REACTIVE PROPERTIES of C36 DIMER ACID:
C36 Dimer Acid is a dicarboxylic acid (two acid functionalities) and exhibits many of the chemical behaviors of long-chain carboxylic acids and unsaturated acids.
C36 Dimer Acid can form metal salts (e.g. lithium, sodium, calcium salts) via neutralization.

C36 Dimer Acid can be converted (via reaction with thionyl chloride / acid chloride formation) to acid chlorides, which then can form amides, esters, diisocyanates, polyamides, polyesters, etc.

The unsaturated bonds (if present in non-hydrogenated C36 Dimer Acid) lend opportunities for further functionalization (e.g. hydrogenation, epoxidation, crosslinking).
C36 Dimer Acid is used as a comonomer in polymer systems (polyamides, polyesters) to impart flexibility, toughness, hydrolytic stability, improved adhesion, etc.

STRUCTURE of C36 DIMER ACID:
the three major isomers of C36 Dimer Acids, I .e., monocyclic, bicyclic and acyclic isomers.
Because the polymerization of unsaturated fatty acids is a complex chemical reaction, the unsaturated fatty acid molecules involved in the reaction can be combined with each other in different ways, thus producing a lot of isomers, such as the double bond of CIS, inverse geometric isomers, component isomers resulting from the "head-to-head" or "head-to-tail" joining of molecules, linear or cyclic structural isomers, and the like.

PHYSICAL PROPERTIES of C36 DIMER ACID:
C36 Dimer Acid has a molecular formula of C36H64O4, a molecular weight of 560.91, and a relative density of 0.95.
Pure C36 Dimer Acid is light yellow transparent viscous liquid, with good thermal stability: no crystallization at low temperature of -20 ℃, no loss of transparent fluidity; No evaporation at 250 ℃, no gelation.

When heated in air, the color will be significantly darker.
Exposure to metal ions, especially copper and iron ions, will promote color deterioration.
Hydrogenated C36 Dimer Acid is an almost colorless, transparent liquid that is less likely to deepen in color even when heated.

C36 Dimer Acid is insoluble in water, but soluble in ether, ethanol, acetone, chloroform, benzene, petroleum solvents.
The structure of the C36 Dimer Acid is also very different due to the different raw materials used.
In the production, different raw materials can be selected according to the requirements of the final product on the structure of the C36 Dimer Acid.

The United States, Japan and other countries mainly to tall oil fatty acid as raw material, in China, most of the soybean oil, cotton oil, sunflower oil, corn germ oil and lower erucic acid rapeseed oil fatty acid as raw material.
Unsaturated fatty acid synthesis of C36 Dimer Acid, the unsaponifiable matter content according to the difference of catalyst and polymerization technology, there is obvious high and low.

High unsaponifiable matter content in 3 ~ 5%; And low unsaponifiable matter content is only 1 ~ 2%.
The commercial C36 Dimer Acid is mainly a single distilled C36 Dimer Acid.
Different varieties of C36 Dimer Acid, its performance is also different, the same variety is also due to the use of different raw materials and the nature of the difference.

Such as the United States dimer content of 87%, 83%, 75% C36 Dimer Acid were high, medium and low grade three ordinary commodity C36 Dimer Acid.
These products are generally referred to as the first distilled or single distilled C36 Dimer Acid, such as the first distilled C36 Dimer Acid distillation again to be distilled C36 Dimer Acid (or double distilled C36 Dimer Acid), the dimer content of up to 95%.

Also known as high-purity C36 Dimer Acid.
If the C36 Dimer Acid is hydrogenated again, a hydrogenated C36 Dimer Acid with very light color and excellent oxidation resistance can be obtained.
High purity C36 Dimer Acid and hydrogenated C36 Dimer Acid are mostly used in some occasions requiring special properties.

PRODUCTION METHOD of C36 DIMER ACID:
from the drying oil, semi-drying oil and other vegetable oils, such as soybean oil, cottonseed oil, rice bran oil containing high linoleic acid, the natural oil of oleic acid is refined to obtain fatty acid, and then prepared by batch pressure catalytic polymerization or continuous catalytic polymerization or intermittent atmospheric pressure methanol vapor oxygen-discharging polymerization.

REACTION MECHANISM of C36 DIMER ACID:
A C36 Dimer Acid is obtained by heat polymerization of an unsaturated fatty acid under the action of a catalyst.
The reaction mechanism of dimerization, at present, the more consistent view is the theory of Diels-Alder addition reaction between conjugated and non-conjugated unsaturated fatty acids.

For example, with cotton oil fatty acid as raw material, the double bond of linoleic acid is co-formed after heating, and oleic acid is dehydrogenated into dienoic acid under the action of catalyst, and the double bond is also co-formed after heating, these two co-substituted dienoic acids become the Diene in the reaction, while the non-conjugated linoleic acid and undehydrogenated oleic acid become the diene affinity in the reaction, both in 1, the addition at the 4-position produces various substituents of cyclohexene C36 Dimer Acids, which are mostly viscous substances.

Of course, two dehydrogenated oleic acid can also be synthesized by free radical reaction, but in the raw materials mainly oleic acid and linoleic acid, most of them are polymerized by Diels-Alder reaction.
The C36 Dimer Acid may also be mixed with other dibasic acids and then mixed with a polyol to form a polyester.

The properties of the mixed polyesters are intermediate between those of the polyesters formed from a single dibasic acid or a C36 Dimer Acid.
This provides advantages for the synthesis of polyesters of various properties.

SYNTHESIS METHOD of C36 DIMER ACID:
The Clay catalytic dimerization method is the most important and most valuable production method in industry.
The White Earth catalyzed dimerization process was first reported in the Johnson patent.
Barrett's patent lists in detail the various types of clay that can be used, and particularly recommends bentonites containing more than 75% silica montmorillonite.

The patent also mentions the acidity of the clay.
The pH of the clay should be between 2 and 7, preferably between 3 and 5.
Subsequently, many patents describe the improvement of the clay catalytic process.

The basic starting point is to improve the dimerization/trimerization ratio and the total product yield.
Adding a small amount of alkali in the reaction mixture can increase the dimerization/trimerization ratio, the bases that can be used are NaOH, Ca(OH)2, Mg(OH)2, Ba(OH)2 and natural alkaline clay.

The patent states that on addition of the base, the reaction temperature must be increased by 10 °c to obtain the same yield.
After the addition of alkali, the dimer obtained by the tall oil fatty acid dimerization had a trimer content of 16%, compared to 20.5% in the absence of alkali.

A method for increasing the dimerization/trimerization ratio is also to add a small amount of ammonia or amine, 1-thio-2-naphthol, arylsulfonyl halide.
The natale et al. patent uses alkaline metal oxide or alkaline earth metal oxide modified clay catalysts for the synthesis of C36 Dimer Acids in a two-step polymerization reaction.

The biggest advantage of this method is: the fatty acid that is not polymerized in the first step is not changed by the catalyst, and the remaining unsaturated acid can be separated and the second polymerization can be continued, the total yield of dimer in two-step polymerization can generally reach 65% ~ 75%.

The dimer has light color and low viscosity; the dimerization/trimerization ratio exceeds that obtained with other catalysts (when the Feedstock consists of tall oil or soybean oil fatty acids, The ratio can reach 8: 1).
Kathrgn combines a certain amount of lithium carbonate, lithium hydroxide or other lithium salts with montmorillonite, Sepiolite and the like as a fatty acid polymerization catalyst, and also adopts a two-step polymerization method to obtain similar results as those of Natale patent.

The disadvantage of the catalytic polymerization of clay is that the clay has to adsorb a certain amount of products.
Discarding clay not only causes product loss, but also causes environmental pollution.

The process developed by Robert et al. to remove fatty acids by washing the clay with hot water at 90 °c overcomes this disadvantage and makes the recovered clay reusable.
Europe and the United States in the 20th century 70~90's about Clay catalyzed dimerization method of many patents, the core technology is to improve the catalytic process, in order to improve the C36 Dimer Acid/trimer acid ratio and the total product yield.

PHYSICAL and CHEMICAL PROPERTIES of C36 DIMER ACID:
Appearance / state: Light yellow to amber, viscous liquid / transparent viscous fluid
Viscosity: For technical / dimer acid product, ~7,500 – 8,500 mPa·s (Brookfield) at 25 °C (as per Royal-Chem data);
For hydrogenated dimer acid (Sigma-Aldrich listing), viscosity ~8,000 mPa·s at 25 °C
Density / specific gravity: ~0.95 g/cm³ at 25 °C (for hydrogenated dimer acid) per Sigma-Aldrich listing;
Some supplier catalogs list ~0.950 g/cm³ (Covalent) as typical
Acid value / acidity: Technical dimer acid (Royal-Chem) cites acid value ~185–198 mg KOH/g
Iodine value: For hydrogenated dimer acid, iodine value < 10 (lit) per Sigma listing
Pour point / transition temperature: For hydrogenated variant, pour point ~0 °C

Refractive index: For hydrogenated dimer acid, n₌¹.⁴⁷⁷ (n_D²⁰) per Sigma listing
Color change / thermal behavior: Dimer acid is reported to darken significantly when heated in air;
under heating to high temperatures, color deepens;
The pure form is said to remain fluid (not gel or evaporate) up to ~250 °C in supplier descriptions
Solubility: Insoluble in water; Soluble in nonpolar and mid-polarity organic solvents:
ether, ethanol, acetone, chloroform, benzene, petroleum solvent series
Vapor pressure: Very low; vapor pressure reported ~0 to 0.029 Pa at 25 °C

LogP / lipophilicity: Very high lipophilicity:
ChemicalBook lists logP at pH 2 between 1 and 14.81 (broad range) for the dimer acid;
Some supplier catalogs list XLogP3 ~14.7 for C36 dimer acid
Boiling point / evaporation: Some sources attempt to list a very high boiling point — e.g.
Chemsrc gives boiling point ~667.7 °C ± 28.0 °C at 760 mmHg (which is likely extrapolated or theoretical);
Covalent lists “> 260 °C” as a boil / decomposition threshold
Compound Canonicalized: Yes

Molecular Weight: 564.9 g/mol
XLogP3-AA: 14.7
Hydrogen Bond Donor Count: 2
Hydrogen Bond Acceptor Count: 4
Rotatable Bond Count: 32
Exact Mass: 564.51176065 Da
Monoisotopic Mass: 564.51176065 Da
Topological Polar Surface Area: 74.6 Å²
Heavy Atom Count: 40
Formal Charge: 0

Complexity: 585
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 2
Defined Bond Stereocenter Count: 1
Undefined Bond Stereocenter Count: 0
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes

CBNumber: CB51011196
Molecular Formula: C36H64O4
Molecular Weight: 560.91
MDL Number: MFCD00163478
MOL File: 61788-89-4.mol
Vapor pressure: 0–0.029 Pa at 25℃
Form: Viscous
InChI: InChI=1S/C36H68O4/c1-3-5-7-9-11-16-22-28-34(30-24-18-14-20-26-32-36(39)40)33(27-21-15-10-8-6-4-2)29-23-17-12-13-19-25-31-35(37)38/h11,16,33-34H,3-10,12-15,17-32H2,1-2H3,(H,37,38)(H,39,40)/b16-11-

InChIKey: AMOKUAKXKXBFIW-WJDWOHSUSA-N
SMILES: C(O)(=O)CCCCCCCC(CC/C=CCCCCC)C(CCCCCCCC)CCCCCCCCC(O)=O
LogP: 1–14.81 at pH2
Indirect Additives used in Food Contact Substances: FATTY ACIDS(C18), UNSATURATED, DIMERS
FDA UNII: 04P17590AP
EPA Substance Registry System: C18-Unsatd. fatty acids dimers (61788-89-4)
CAS No.: 61788-89-4
Chemical Name: C36 Dimer acid

Molecular Formula: C36H68O4
Formula Weight: 564.92272
Molecular Weight: 560.91
Dimer: ≥80.0%
Trimer: ≤20.0%
Appearance at 25℃: Clear amber colored low viscous liquid
Acid Value (mgKOH/g): 185–198
Color (Gardner): ≤8
Monomer (including intermediate): ≤5%
Saponification Value (mgKOH/g): 195–204

Viscosity 25℃ (mPa.s) #Brookfield: 7500–8500
Phosphorus: ≤10 ppm
Fe: ≤2 ppm
Compound Canonicalized: Yes
CBNumber: CB51011196
Molecular Formula: C36H64O4
Molecular Weight: 560.91
MDL Number: MFCD00163478
MOL File: 61788-89-4.mol

Vapor Pressure: 0-0.029Pa at 25℃
Form: Viscous
LogP: 1-14.81 at pH2
Indirect Additives used in Food Contact Substances:
FATTY ACIDS(C18), UNSATURATED, DIMERS
FDA UNII: 04P17590AP
EPA Substance Registry System: C18-Unsatd.
fatty acids dimers (61788-89-4)

Molecular Weight: 564.92
Appearance: Brown, viscous liquid
Density: 0.950 g/cm3
Assay: 70 - 85% (Dibasic Acid)
Boiling Point: > 260°C
Melting Point: -18°C (pour point)
Flash Point: > 257°C
Odor: Mild fatty
Acid Value: 181 MIN.

Class: Dimer Acids and Trimer Acids
Assay: 95.00 to 100.00
Food Chemicals Codex Listed: No
Boiling Point: 360.60°C @ 760.00 mm Hg (est)
Vapor Pressure: 0.000004 mmHg @ 25.00°C (est)
Flash Point: 523.00°F TCC (273.00°C) (est)
logP (o/w): 7.180 (est)
Soluble in: water, 0.03771 mg/L @ 25°C (est)

Molecular Weight: 564.92
Appearance: Brown, viscous liquid
Density: 0.950 g/cm3
Assay: 70 - 85 % (Dibasic Acid)
Boiling Point: > 260°C
Melting Point: -18°C (pour point)
Flash Point: > 257°C
Odor: Mild fatty
Acid Value: 181 MIN.

Class: Dimer Acids and Trimer Acids
Market: Oleochemicals
CAS: 61788-89-4
EINECS: 500-148-0
InChI: InChI=1/C36H68O4/c1-3-5-7-9-11-16-22-28-34(30-24-18-14-20-26-32-36(39)40)33(27-21-15-10-8-6-4-2)29-23-17-12-13-19-25-31-35(37)38/h11,16,33-34H,3-10,12-15,17-32H2,1-2H3,(H,37,38)(H,39,40)/b16-11-
Molecular Formula: C36H64O4
Molar Mass: 560.91

Density: 0.931 g/cm3
Boiling Point: 667.7°C at 760 mmHg
Flash Point: 371.6°C
Vapor Pressure: 0–0.029 Pa at 25°C
Appearance: Viscous
Storage Condition: Room Temperature
Refractive Index: 1.478
Molecular Weight: 560.91 g/mol
Molecular Formula: C36H64O4
Compound Is Canonicalized: True

XLogP3-AA: 14.7
Exact Mass: 564.51176065
Monoisotopic Mass: 564.51176065
Complexity: 585
Rotatable Bond Count: 32
Hydrogen Bond Donor Count: 2
Hydrogen Bond Acceptor Count: 4
Topological Polar Surface Area: 74.6
Heavy Atom Count: 40

Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 2
Defined Bond Stereocenter Count: 1
Undefined Bond Stereocenter Count: 0
Isotope Atom Count: 0
Covalently-Bonded Unit Count: 1
CACTVS Substructure Key Fingerprint:
PSA: 74.6

XLogP3: 14.79
Appearance: Liquid; PelletsLargeCrystals
Density: 0.9±0.1 g/cm3
Boiling Point: 667.7±28.0 °C at 760 mmHg
Flash Point: 371.6±20.5 °C
Refractive Index: 1.479
Product Name: Unsaturated fatty acids, C18, dimers
CAS No.: 61788-89-4

InChIKeys: AMOKUAKXKXBFIW-WJDWOHSUSA-N
Molecular Weight: 560.91
Exact Mass: 564.511780
EC Number: 500-148-0
DSSTox ID: DTXSID2028062
CAS No.: 61788-89-4
Formula: C36H68O4
Appearance: Liquid

Product Name: 61788-89-4
CAS: 61788-89-4
Assay: 95.00 to 100.00
Food Chemicals Codex Listed: No
Boiling Point: 360.60°C @ 760.00 mm Hg (est)
Vapor Pressure: 0.000004 mmHg @ 25.00°C (est)
Flash Point: 523.00°F TCC (273.00°C) (est)
logP (o/w): 7.180 (est)
Soluble in: water, 0.03771 mg/L @ 25°C (est)
Compound Canonicalized: Yes

FIRST AID MEASURES of C36 DIMER ACID:
-Description of first-aid measures:
*If inhaled:
If breathed in, move person into fresh air.
*In case of skin contact:
Wash off with soap and plenty of water.
*In case of eye contact:
Flush eyes with water as a precaution.
*If swallowed:
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
-Indication of any immediate medical attention and special treatment needed:
No data available

ACCIDENTAL RELEASE MEASURES of C36 DIMER ACID:
-Environmental precautions:
Do not let product enter drains.
-Methods and materials for containment and cleaning up:
Keep in suitable, closed containers for disposal.

FIRE FIGHTING MEASURES of C36 DIMER ACID:
-Extinguishing media:
*Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
-Further information:
No data available

EXPOSURE CONTROLS/PERSONAL PROTECTION of C36 DIMER ACID:
-Control parameters:
--Ingredients with workplace control parameters:
-Exposure controls:
--Personal protective equipment:
*Eye/face protection:
Use equipment for eye protection.
*Skin protection:
Handle with gloves.
Wash and dry hands.
*Body Protection:
Impervious clothing
*Respiratory protection:
Respiratory protection not required.
-Control of environmental exposure:
Do not let product enter drains.

HANDLING and STORAGE of C36 DIMER ACID:
-Conditions for safe storage, including any incompatibilities:
*Storage conditions:
Store in cool place.
Keep container tightly closed in a dry and well-ventilated place.
Containers which are opened must be carefully resealed and kept upright to prevent leakage.

STABILITY and REACTIVITY of C36 DIMER ACID:
-Reactivity:
No data available
-Chemical stability:
Stable under recommended storage conditions.
-Possibility of hazardous reactions:
No data available
-Conditions to avoid:
No data available