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Isophorone Diisocyanate, called Isophorone Diisocyanate in Turkish, is a cycloaliphatic diisocyanate with the molecular formula C₁₂H₁₈N₂O₂ and carrying two reactive isocyanate groups. This raw material, identified by CAS No 4098-71-9, is particularly used in the preparation of high-performance polyurethane resins, coatings, adhesives, elastomers, and water-based polyurethane dispersions.
One of the standout features of Isophorone Diisocyanate is its cycloaliphatic structure, which does not contain aromatic rings. This structure, along with the appropriate resin system, can help reduce light-induced discoloration in clear, white, or light-colored polyurethanes and maintain the appearance of the outdoor environment for a longer period of time.
The chemical environments of the two NCO groups involved in the Isophorone Diisocyanate molecule are not identical. This structural asymmetry can create a difference in reaction rates, allowing for more precise management of the molecule structure and the level of residual free monomers in controlled prepolymer syntheses.
Isophorone Diisocyanate can react with polyether, polyester, polycarbonate, and other hydroxyl functional polyols.
Isophorone Diacyanate generally provides hydrolysis resistance, low-temperature flexibility, and elasticity, while polyester polyols provide stiffness, abrasion resistance, and resistance to oils or solvents.
The combination of isophorone Diocyanate chosen depends on whether the final polyurethane is intended for coating, bonding, elastomer, dispersion, or specialty resin.
When Isophorone Diisocyanate reacts with polyols, it forms urethane bonds, and when it reacts with primary or secondary amines, it forms urea bonds. Therefore, coating resin, elastomer, adhesive prepolymer, polyurethane dispersion, and numerous special intermediates can be developed from a single monomer.
Isophorone Diisocyanate is also important as a starting raw material in the production of higher-functioning crosslinkers. IPDI isocyanurates, IPDI trimers, blocked polyisocyanates, urethane acrylates, and silane-function polyurethanes are among the major product groups that can be derived from this chemical.
In commercial high-purity grades of Isophorone Diisocyanate, the NCO content can be found at approximately 37.5–37.8% and the purity at least approximately 99.5%. Color, total chlorine, viscosity and trace impurities are important quality criteria, especially in the synthesis of transparent resin, controlled prepolymer and high-performance polyurethane.
Isophorone Diisocyanate cycloaliphatic structure, polyurethane adds rigidity and rigidity to hard segments.
At the same time, the absence of aromatic rings gives IPDI-based systems significantly greater resistance to light-induced yellowing than many aromatic isocyanate-based polyurethane systems.
The combination of Isophorone Diisocyanate ensures that formulations provide durability without compromising the appearance required for exterior or transparent applications.
The low viscosity liquid form of Isophorone Diisocyanate can facilitate mixing, pumping and dosing. The very low solidification temperature also supports the ability to keep the product in a liquid state over a wide range of process temperatures.
Because Isophorone Diisocyanate reacts with water, moisture control is one of the key requirements during storage and synthesis. Unintended water contact can lead to the depletion of NCO groups, the formation of carbon dioxide, and problems such as bubbles, pores, or viscosity changes in coating or casting systems.
Isophorone Diisocyanate; It can be evaluated with different functions in automotive, industrial coating, leather, textile, adhesive, sealant, elastomer and special resin technologies. The final performance depends not only on the type of diisocyanate, but also on the polyol structure, NCO/OH ratio, catalyst system, additives and curing conditions.
WHAT IS ISOPHORONE DIISOCYANATE?
Isophorone Diisocyanate is a cycloaliphatic organic compound with two isocyanate functional groups. Its chemical name is given as 3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl Isocyanate. The commercial product is usually a clear, colorless to slightly yellow liquid with low viscosity.
The molecule is built on a substituted cyclohexane ring carrying three methyl groups. One of the isocyanate groups is located on the ring and the other on the isocyantomethyl side group.
This structural arrangement makes Isophorone Diisocyanate an unsymmetrical diisocyanate. The presence of NCO groups in different steric environments creates a difference in reactivity, which can be used especially in controlled polyurethane syntheses.
The nominal functionality of Isophorone Diisocyanate is 2. The theoretical NCO equivalent weight is calculated to be approximately 111.1 g/eq based on a molecular weight of approximately 222.28 g/mol.
The theoretical NCO content is approximately 37.8%. An NCO range of approximately 37.5–37.8% and a purity of at least 99.5% can be commonly seen in current high-purity commercial products.
The different reactivity of the two NCO groups of Isophorone Diisocyanate is particularly important in the production of prepolymers. Under favorable temperature and catalyst conditions, the reaction can be conducted more selectively, facilitating the preparation of intermediates with the desired end-group structure.
Isophorone Diisocyanate is insoluble in water and reacts chemically when exposed to water or atmospheric moisture.
Water contact depletes the isocyanate groups and produces carbon dioxide along with insoluble polyurea products.
Therefore, moisture must be excluded from storage tanks, drums, transfer lines, solvents, and processing equipment used with Isoforone Diisocyanate.
A water reaction with Isophorone Diisocyanate can create pressure in a sealed contaminated container.
The production of carbon dioxide is particularly important because even a relatively small amount of water can produce solid polyurea deposits while simultaneously producing gas.
Therefore, contaminated containers should never be treated as ordinary sealed liquid-chemical packets without the relevant emergency procedure.
Isophorone Diisocyanate is supplied commercially as a high-purity monomeric diocyanate.
Isophorone Diisocyanate has a purity of at least 99.5%, NCO content of 37.5–37.8%, total chlorine not exceeding approximately 400 ppm, and hydrolyzable chlorine not exceeding approximately 200 ppm as the representing industrial specification.
These parameters are important because impurities can affect polyurethane reaction behavior, product color, and catalyst response.
Specifications related to chlorine are particularly important for technical purchasing.
Hydrolyzable chlorine and total chlorine can provide information about production consistency and influence subsequent polyurethane processing or catalyst requirements.
This approach can contribute to the development of polyurethane intermediates with lower viscosity and more controlled molecular weight distribution. It can also be used in process designs that aim to reduce the level of free monomers.
Isophorone Diisocyanate, together with polyether polyols, can be evaluated in products with priority on flexibility and hydrolysis resistance. With polyester polyols, mechanical strength, abrasion resistance and resistance to certain chemical environments can be improved.
Polycarbonate polyols can be preferred in special coating and dispersion systems where higher durability and hydrolysis resistance are targeted. The grade of polyol used significantly changes the performance profile of the final polyurethane.
The cycloaliphatic ring of Isophorone Diisocyanate can impart rigidity to the rigid segment of the polymer. Therefore, it is an important building block in applications where hardness and surface strength are desired in combination with color stability.
The absence of aromatic rings may result in a lower tendency to yellow under light compared to MDI and TDI-based polyurethanes. Transparent automotive topcoats, light-colored elastomers and decorative coatings are applications where this feature is important.
Isophorone Diisocyanate is also the production raw material of IPDI trimers and other polyisocyanates. These derivatives can have higher functionality than the monomeric product and are used differently as a coating hardener.
Blocked IPDI derivatives can also be prepared from Isophorone Diisocyanate. In these products, NCO groups are temporarily sealed to the reaction, making it possible to prepare one-component and heat-cured systems.
These reactions are fundamental to polyurethane, polyurea, moisture curing and waterborne resin technologies based on Isophorone Diisocyanate.
This lower inherent reactivity gives formulators additional control over polyurethane synthesis while often catalytic acceleration is desirable when rapid urethane formation is required.
The choice of catalyst depends on the specific resin, processing temperature, pot life, and final application.
Isophorone Diisocyanate is particularly important in situations where polyurethane products need to maintain color, brightness, and mechanical properties during exposure to light and outdoor weather conditions.
COMMON PRODUCT AND CHEMICAL NAMES
Isophorone Diisocyanate
Isophorone Diisocyanate
IPDI
Monomeric IPDI
Monomeric IPDI
Isophorone Di-isocyanate
3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl Isocyanate
3-Isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate
5-Isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane
1-Isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane
Isophorone Diamine Diisocyanate
Cycloaliphatic Diisocyanate
Monomeric Cycloaliphatic Diisocyanate
C₁₂H₁₈N₂O₂
CAS 4098-71-9
EC 223-861-6
VESTANAT IPDI
Desmodur I
CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION
Product Name: Isophorone Diisocyanate
Turkish name: Isophorone Diisocyanate
Chemical name: 3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl Isocyanate
Abbreviation: IPDI
CAS No: 4098-71-9
EC/EINECS No: 223-861-6
Molecular formula: C₁₂H₁₈N₂O₂
Molecular weight: Approximately 222.28 g/mol
Chemical class: Cycloaliphatic diisocyanate
Functionality: 2
Theoretical NCO content: Approximately 37.8%
Commercial NCO content: Approx. 37.5–37.8%
NCO equivalent weight: Approx. 111.1 g/eq
Purity: Approximately 99.5% ≥ in high-purity commercial products
Physical form: Clear, colorless to slightly yellow liquid
Its main functions: Polyurethane raw material, prepolymer raw material, polyisocyanate precursor, polyurethane dispersion raw material and special resin building block
Isophorone Diisocyanate is a monomeric diisocyanate with a defined molecular structure. The molecular weight, theoretical functionality and theoretical NCO content can therefore be calculated directly.
Commercial quality differences are more commonly associated with product purity, color, total chlorine, and other trace impurities. In sensitive polyurethane synthesis, these values may be important for process reproducibility.
Current high-purity VESTANAT IPDI data state NCO content of 37.5–37.8% and purity of at least 99.5%. The same product data also describe additional physical properties such as density, viscosity, color, and vapor pressure.
CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF ISOPHORONE DIISOCYANATE
Isophorone Diisocyanate has an asymmetric diisocyanate structure built on a substituted cyclohexane ring. The three methyl groups in the ring affect the steric environment and the physical behavior of the molecule.
The absence of two NCO groups in the same position distinguishes their reaction behavior. This difference is particularly valuable for controlled propolymer production and functional intermediate synthesis.
The carbon atom of the isocyanate group has an electrophilic character. Nucleophilic groups, such as hydroxyl or amine, react with this center, allowing the formation of new covalent bonds.
When Isophorone Diisocyanate reacts with the OH group in the polyol, a urethane bond is formed. As this reaction repeats, high molecular weight polyurethane chains can be developed.
As a result of the reaction with amines, urea bonds are formed. The high speed of the amine-isocyanate reaction can be used, especially in the chain extension stage of polyurethane dispersions.
In the reaction with water, the intermediate is unstable and carbon dioxide is released. As a result of the ongoing reaction, urea structures can be formed.
Therefore, Isophorone Diisocyanate's contact with moisture should be controlled. The presence of water in the sealed packaging or tank may also pose a risk in terms of gas formation and pressure increase.
The cycloaliphatic ring forms a non-aromatic hard segment. This structure provides an advantage in terms of color stability and outdoor appearance of polyurethane.
The irregular molecular geometry of Isophorone Diisocyanate reduces its tendency to crystallize. The solidification temperature of around -60 °C makes it easy for the product to remain liquid in many industrial conditions.
Low viscosity provides advantages in terms of mixing and heat transfer. This property can be especially evaluated in high-solids systems and low-viscosity prepolymer development studies.
Isophorone Diisocyanate ester can be used in polyurethane systems compatible with ketones, ether esters and many organic solvents with aromatic structures. However, the solvent water content should always be controlled.
The different reactivity of the two NCO groups of Isophorone Diisocyanate can change with temperature. Low temperature and appropriate catalyst use can make greater use of selective reaction behavior.
This property may become important when designing sequential reactions with compounds such as acrylates with hydroxyl function, specialized polyols, or silanes.
PHYSICAL AND CHEMICAL PROPERTIES OF ISOPHORONE DIISOCYANATE
Isophorone Diisocyanate is a clear and low viscosity liquid under normal conditions. Measurement values may vary slightly depending on the commercial grade used and test conditions.
General technical specifications:
Physical appearance: Clear liquid between colorless and slightly yellow
Odor: Mild but characteristic
Chemical character: Cycloaliphatic diisocyanate
Molecular formula: C₁₂H₁₈N₂O₂
Molecular weight: Approximately 222.28 g/mol
CAS No: 4098-71-9
EC/EINECS No: 223-861-6
Functionality: 2
NCO content: Approx. 37.5–37.8%
Purity: About ≥99.5%
NCO equivalent weight: Approx. 111.1 g/eq
Density: Approx. 1.058 g/cm³, 20 °C
Viscosity: Approx. 13–15 mPa·s, 23 °C
Colour: 10< APHA in a current high-purity commercial product
Refractive index: Approx. 1,483, 25 °C
Solidification/freezing point: About -60°C
Vapor pressure: Approx. 6.35 × 10⁻⁴ hPa, 20 °C
Flash point: Approx. 151 °C, closed cup
Autoignition temperature: Approx. 430 °C
Total chlorine: 10≤ ppm typical value in a current high-purity commercial product
NIOSH specific gravity value: Approx. 1.06
NIOSH vapor pressure: About 0.0003 mmHg
NIOSH freezing point: About -76 °F
Behavior in water: Shows chemical reaction
The low viscosity of Isophorone Diisocyanate can be advantageous in terms of pumping and mixing the reaction mixture. The final prepolymer viscosity can be much higher depending on the polyol used and the degree of reaction.
Very low vapor pressure indicates limited volatility at normal temperature. However, in the formation of spraying or aerosols, airborne droplets remain important in terms of exposure.
The solidification temperature is notably low, which can reduce the risk of crystallization during storage. This feature provides a practical advantage, especially in logistics and manufacturing environments where temperature variation occurs.
These values are given for general technical promotion purposes. The acceptance criteria of the purchased product should be based on the current TDS and batch COA values.
HOW DOES ISOPHORONE DIISOCYANATE WORK AT THE MOLECULAR LEVEL?
The primary function of Isophorone Diisocyanate is to react with active hydrogen-bearing molecules to become part of a polyurethane or polyurethane-urea structure. When the hydroxyl group in the polyol reacts with the NCO group, a urethane bond is formed. The repeated reaction of bifunctional raw materials enables the development of long polymer chains. When polyol functionality increases, branching and cross-linking can increase in the system. Thus, polyurethane structures with thermoset or higher mesh density can be formed.
The reaction with amines results in the formation of urea groups. These bonds can play an important structural role, especially in polyurethane-urea elastomers and water-based dispersions.
The reactivity of Isophorone Diisocyanate is generally more controlled than that of aromatic diisocyanates. Therefore, catalyst can be used to achieve the desired reaction rate in some systems.
The different reactivity of the NCO groups allows for additional control in the prepolymer design. More selective conversion can be achieved when the reaction temperature and catalyst are selected correctly.
At the molecular level, the main functions of Isophorone Diisocyanate are:
Creating a urethane bond with polyols
Forming urea bonds with amines
Creating polyurethane chain
Preparing the prepolymer
To produce water-based polyurethane dispersion
Polyurethane-urea structure develop
Preparing moisture-curing systems
To be the raw material of IPDI trimers
Producing polyisocyanate hardener
Producing blocked crosslinker
Synthesizing urethane acrylate
Being a building block for UV-curing resins
Preparing polyurethane with silane function
Producing urethane modified alkyd
Creating a hard segment with low yellowing tendency
Supporting film stiffness and chemical resistance
IN WHICH SECTORS IS ISOPHORONE DIISOCYANATE USED?
Isophorone Diisocyanate is an important intermediate raw material, especially in sectors where high-performance polyurethane materials are used. The mode of application varies depending on whether the monomer is used directly in resin synthesis or the polyisocyanates derived from it in the final formulation.
Main areas of use:
Automotive OEM coatings
Automotive refinish coatings
Transparent topcoats
Commercial vehicle wraps
Industrial metal coatings
Outdoor protective coatings
Wood varnishes
Transparent wood veneers
Plastic coatings
High-solids coatings
Solvent-based polyurethane resins
Waterborne polyurethane dispersions
Polyurethane adhesives
Shoe adhesives
Laminating adhesives
Automotive interior trim adhesives
Reactive hot melt adhesives
Moisture-curing adhesives
Construction adhesives
Polyurethane sealants
Automotive sealants
Construction grouts
Polyurethane elastomers
Light-colored cast elastomers
RIM systems
Artificial skin resins
Natural leather finishes
Textile coatings
Flexible polyurethane films
Protective membranes
Urethane acrylates
UV-curing coatings
UV-curing inks
Radiation curing resins
Silane terminated polyurethanes
Hybrid adhesives and sealants
IPDI trimer production
Production of IPDI polyisocyanate
Blocked IPDI derivatives
Urethane modified alkyd resins
Special casting and tool resins
One of the areas where Isophorone Diisocyanate is strong in polyurethane technologies with high light and outdoor resistance. Better color preservation can be achieved in transparent or light-colored products compared to aromatic diisocyanates.
Water-based polyurethane dispersions are also one of the important uses. The low prepolymer viscosity can facilitate the dispersion process in water and contribute to reducing the need for co-solvents.
PAINT, COATING, POLYURETHANE AND RESIN APPLICATIONS OF ISOPHORONE DIISOCYANATE
Paint and coating technology are among the most important uses of Isophorone Diisocyanate. The monomeric product is often considered as a starting material in the production of higher-functioning polyisocyanates or polyurethane resins.
Possible functions of Isophorone Diisocyanate in coating applications include:
Producing light-resistant polyurethane resin
Developing outdoor coatings
Reducing yellowing on transparent films
Supporting color retention in white coatings
To produce IPDI-based polyisocyanates
Preparing isocyanurate type hardeners
Producing blocked crosslinkers
Preparing water-based polyurethane resins
Producing low-viscosity prepolymers
Developing high-solids coatings
Preparing urethane acrylate
Improving film stiffness
Increasing chemical resistance
Supporting scratch and abrasion resistance
Contributing to shine preservation
Maintaining the appearance of automotive finishes
Automotive transparent topcoats are classic applications of IPDI derivatives. With prolonged sun exposure, it is desirable that the coating yellows as little as possible and retains its shine.
IPDI-based polyisocyanates can be used in combination with hydroxyl-function acrylic or polyester resins. Thus, two-component polyurethane coatings with high cross-link density can be created.
Maintaining the natural surface color is important for wood varnishes. Cycloaliphatic polyurethane chemistry can help limit yellowing.
In plastic coatings, hardness, flexibility and adhesion to the surface are evaluated together. When the Isophorone Diisocyanate-based hard segment is balanced with the appropriate polyol structure, these properties can be developed together.
Viscosity needs to be limited in high-solids coating systems. Low viscosity Isophorone Diisocyanate and suitable prepolymer design can be considered for resins where the amount of solvent is reduced.
In the production of urethane acrylate, Isophorone Diisocyanate can be reacted with acrylates with hydroxyl function. The resulting oligomers can be cured quickly with UV or electron beam.
USE OF ISOPHORONE DIISOCYANATE IN ADHESIVE, SEALING, ELASTOMER AND WATER-BASED POLYURETHANE APPLICATIONS
Isophorone Diisocyanate can be used for the synthesis of different polyurethane intermediates in adhesive and sealing technology. Water-based dispersions, NCO tipped prepolymers, and silane-terminated resins are the principal ones.
In water-based polyurethane dispersion, a controlled prepolymer is first prepared. Then, the polymer, which is given hydrophilic properties, is dispersed in water as fine particles.
Prepolymer viscosity is an important parameter at this stage. Low viscosity can provide easier dispersion and lower co-solvent requirements.
Flexibility and strong bonding are desired together in shoe adhesives. Polyurethane dispersions based on Isophorone Diisocyanate can be used in joining leather, textile and synthetic surfaces.
Laminating adhesives can be used to join films, fabrics, foams, and membranes. The choice of polyol used determines the flexibility and hydrolysis resistance of the final adhesive.
In reactive hot melt adhesives, the pre-polymer is applied by heating. While cooling provides initial strength, the ongoing reaction with moisture contributes to the development of final strength.
Polyurethane prepolymers with NCO tips can be used in moisture-curing sealants. The moisture taken from the air allows the network structure to form.
Yellowing can be significant in light-colored adhesives and sealants. The cycloaliphatic nature of Isophorone Diisocyanate may provide an advantage over aromatic diisocyanates in such products.
Artificial leather and natural leather surface coatings are also among the uses of Isophorone Diisocyanate-based polyurethanes. The film should be both flexible and retain its color in long-term use.
IS ISOPHORONE DIISOCYANATE USED IN FOOD, COSMETIC AND PHARMACEUTICAL APPLICATIONS?
Isophorone Diisocyanate is mainly the reactive raw material used in the synthesis of industrial polyurethane. It is not a direct food ingredient, flavoring agent or food additive.
There is no food ID for Isophorone Diisocyanate that qualifies as a FEMA, JECFA, or E number. The monomeric product should therefore not be evaluated directly in food formulation.
The suitability of the final polymer in food contact adhesive or coating systems should be evaluated separately. Free monomer, migration and target country legislation are important in this evaluation.
In cosmetic products, monomeric Isophorone Diisocyanate is not a general-purpose raw material. Due to its reactive isocyanate structure, it is not considered a typical ingredient to be used in end-consumer cosmetic formulations.
It is not the standard active substance or excipient in the pharmaceutical industry. Certain research or synthesis applications should be evaluated separately.
In medical device polyurethanes, the regulatory status of the monomer and the final polymer should be distinguished from each other. The final material should be examined separately for biocompatibility and the remaining monomer.
The following functions may come to the fore in industrial Isophorone Diisocyanate applications:
Polyurethane synthesis
Prepolymer production
Production of water-based polyurethane dispersion
Polyurethane-urea synthesis
IPDI trimer production
Production of polyisocyanate hardener
Production of blocked polyisocyanate
Two-component paint hardener raw material
One-component furnace system crosslinker raw material
Production of moisture-curing prepolymer
Production of adhesive resin
Production of sealing polymer
Elastomer production
Production of artificial skin resin
Textile coating resin production
Production of urethane acrylate
Production of UV-cured resin
Production of silane-terminated polyurethane
Production of urethane modified alkyd
Development of high-solids coating resin
Production of low-free monomer prepolymer
Transparent resins with high light resistance
Outdoor resistant coatings
The NCO/OH ratio is the basic calculation parameter in polyurethane synthesis. The ratio between isocyanate and hydroxyl equivalents affects molecular weight, cross-linking, and the amount of NCO remaining.
The polyol hydroxyl number is used to calculate the amount of Isophorone Diisocyanate used. A high hydroxyl count indicates that there are more reactive groups in the same mass.
Polyol functionality influences the development of network structure. Bifunctional polyols can form more linear structures, while higher-function polyols can form more branched structures.
Moisture in the reaction system should be controlled as much as possible. Water can cause unwanted consumption of NCO groups.
The following issues should be evaluated in the use of Isophorone Diisocyanate in industrial systems:
Product purity
NCO content
Color value
Viscosity
Total chlorine
Hydrolysis can chlorine
Polyol type
Polyol hydroxyl number
Polyol functionality
Polyol moisture content
Solvent moisture
NCO/OH ratio
Type of catalyst
Catalyst quantity
Reaction temperature
Feed rate
Reaction time
Remaining NCO amount
Free amount of Isophorone Diisocyanate
Prepolymer viscosity
Chain extender type
Dispersion particle size
Solids ratio
Ultimate film hardness
Flexibility
Adhesion
Abrasion resistance
Chemical resistance
Yellowing resistance
Outdoor performance
TDS
SDS
COA
WHAT PROBLEMS CAN ISOPHORONE DIISOCYANATE HELP SOLVE?
Isophorone Diisocyanate; It can help solve various technical problems such as yellowing, high pre-polymer viscosity, external strength and the need for controlled reaction in polyurethane systems. However, real performance depends on the design of the entire resin system together.
Yellowing of aromatic polyurethanes
MDI or TDI-based polyurethanes can show significant color change under light. The cycloaliphatic nature of Isophorone Diisocyanate can help mitigate this issue.
Color protection in clear coats
The color from the raw material or resin is easily noticeable on transparent surfaces. Low color high purity Isophorone Diisocyanate can contribute to the preparation of lighter colored polyurethane resins.
Inadequate appearance protection in outdoor coatings
Sunlight and weather conditions can lead to loss of brightness and color. IPDI-based polyisocyanates in combination with the appropriate resin can help maintain the appearance of the outdoor environment.
High prepolymer viscosity
Excessively high viscosity can complicate mixing and pumping processes. Isophorone Diisocyanate's low viscosity and selective reaction behavior can support the development of prepolymers that are more easily processed.
High solvent requirement in waterborne dispersion
Co-solvent may be required to disperse high-viscosity prepolymers into water. IPDI chemistry, which provides lower viscosity, can contribute to reducing this need.
High free monomer in the prepolymer
Using reaction selectivity and setting the stoichiometry correctly can help reduce the amount of monomers remaining. This requires real process optimization.
Yellowing of light-colored mastics
Aromatic polyurethane sealants may yellow over time in visible areas. Isophorone Diisocyanate-based systems can be considered for better color retention.
Color reproduction in UV-cured systems
Aromatic urethane acrylates can cause unwanted yellowing in clear coatings. IPDI-based urethane acrylates can be used in the development of lower color systems.
Insufficient hardness in the coating
The cycloaliphatic ring can contribute to rigid segment rigidity. Film stiffness can be increased with appropriate cross-link density.
Insufficient chemical resistance
Insufficient mesh density can reduce resistance to solvents and cleaners. IPDI-based high-functioning polyisocyanates can provide denser cross-linking with the appropriate resin.
Failure to establish the balance of hardness and flexibility
Excessive increase in hardness can create brittleness. IPDI derivatives can be balanced with other components such as flexible polyols or HDI-based polyisocyanates.
It should not be assumed that every source of Isophorone Diisocyanate will give the same process result. The new source of raw material must be evaluated by comparative laboratory trials.
THINGS TO CONSIDER WHEN USING ISOPHORONE DIISOCYANATE
One of the most important process issues in the use of Isophorone Diisocyanate is humidity control. Since water reacts with NCO groups, the raw material, solvent and equipment must be kept dry.
The following issues should be considered when using Isophorone Diisocyanate:
It should be verified that the product is monomeric Isophorone Diisocyanate.
The CAS number should be checked.
The purity value should be examined.
The NCO content should be checked.
The color value should be evaluated.
Total chlorine should be checked.
Hydrolysis may be checked if chlorine is required.
The polyol hydroxyl number should be known.
Polyol functionality should be considered.
Polyol moisture should be controlled.
It should be ensured that the solvents are dry.
NCO/OH equivalent calculation should be made.
The reactor must be kept dry.
The feed rate should be controlled.
The reaction temperature should be monitored.
Exothermic behavior should be considered.
The choice of catalyst should be based on the application.
The catalyst level must be optimized.
The remaining amount of NCO should be analyzed.
The amount of free Isophorone Diisocyanate should be measured as needed.
The pre-polymer viscosity should be monitored.
Moisture ingress must be prevented during storage.
The transfer equipment must be kept dry.
Aerosol formation should be reduced.
TDS should be examined.
SDS should be examined.
Batch values must be verified via COA.
Monomeric Isophorone Diisocyanate is not the same product as IPDI trimer or other IPDI polyisocyanates. Functionality, equivalent weight and usage patterns are different.
Since the reaction with the polyol is exothermic, the temperature and feed rate must be carefully controlled in large-volume production. Reactor cooling capacity is an important part of the process design.
Spraying or aerosol-forming processes should be evaluated separately in terms of occupational health. Current SDS and relevant legislation should be taken as basis.
INITIAL FORMULATION APPROACHES FOR ISOPHORONE DIISOCYANATE
Isophorone Diisocyanate can be evaluated at approximately 15–25% of the total formulation for initial studies in polyurethane prepolymer formulations; 19% Isophorone Diisocyanate can be used as a practical first trial point. The exact percentage of use should be recalculated based on the hydroxyl number of the polyol used and the targeted NCO/OH ratio.
The following examples are intended to illustrate how Isophorone Diisocyanate can be evaluated in formulation and process development studies. These are not verified commercial recipes or direct manufacturing instructions.
Actual proportions should be calculated based on the batch NCO content of IPDI, polyol hydroxyl number, and targeted final properties.
EXAMPLE 1: ISOPHORONE DIISOCYANATE / POLYOL NCO/OH RATIO SCAN
Purpose: To compare the effect of different NCO/OH ratios on prepolymer viscosity, amount of remaining NCO, and free monomer level.
Starting components:
Sample 1 – target NCO/OH approx. 1.5:
Polyol, approx. 56 mg KOH/g OH: 85.72%
Isophorone Diisocyanate: 14.26%
Catalyst: 0.02%
Total: 100%
Sample 2 – target NCO/OH approx. 1.8:
Polyol, approx. 56 mg KOH/g OH: 83.34%
Isophorone Diisocyanate: 16.64%
Catalyst: 0.02%
Total: 100%
Sample 3 – target NCO/OH approx. 2.0:
Polyol, approx. 56 mg KOH/g OH: 81.83%
Isophorone Diisocyanate: 18.15%
Catalyst: 0.02%
Total: 100%
Sample 4 – target NCO/OH approx. 2.2:
Polyol, approx. 56 mg KOH/g OH: 80.37%
Isophorone Diisocyanate: 19.61%
Catalyst: 0.02%
Total: 100%
Application approach:
The actual hydroxyl value of the polyol is determined.
The actual NCO value of Isophorone Diisocyanate is taken from the COA.
The above percentages are the sample starting calculation for a polyol with a OH value of approximately 56 mg KOH/g.
When different polyol is used, the percentage of Isophorone Diisocyanate is recalculated.
Polyol moisture is controlled.
Isophorone Diisocyanate is added to the reactor in a controlled manner.
Temperature change is monitored.
NCO analysis is performed at regular intervals.
When the target value is reached, the reaction is terminated.
Viscosity is measured.
Color is controlled.
If necessary, the free monomer is analyzed by chromatographic method.
The most balanced sample is taken to subsequent application tests.
EXAMPLE 2: ISOPHORONE DIISOCYANATE-BASED WATER-BASED POLYURETHANE DISPERSION SCAN
Purpose: To evaluate the effect of the amount of Isophorone Diisocyanate on dispersion particle size, film hardness, flexibility and water resistance.
Starting components:
Polyol: 28.00%
Isophorone Diisocyanate: 11.00%
Internal hydrophilic component: 2.50%
Neutralizing agent: 1.90%
Chain extender: 1.40%
Co-solvent: 5.20%
Deionized water: 50.00%
Total: 100%
Application approach:
The moisture content of the reactive raw materials is controlled.
Isophorone Diisocyanate is added to the polyol phase in a controlled manner.
The prepolymer is reacted up to the target NCO value.
If necessary, the ionic groups are neutralized.
The prepolymer is dispersed in water in a controlled manner.
Chain extension is carried out.
pH and solids are adjusted.
The particle size is measured.
Viscosity is monitored.
Storage stability is checked.
Standard film is prepared.
Hardness, flexibility, adhesion and water resistance are compared.
EXAMPLE 3: COATING SCREENING WITH ISOPHORONE DIISOCYANATE DERIVATIVE POLYISOCYANATE
Objective: To evaluate the effect of IPDI-based polyisocyanate level on coating hardness, chemical resistance and outdoor appearance.
Starting components:
Resin with hydroxyl function: 55.00%
IPDI-based low-monomer polyisocyanate: 20.00%
Suitable solvent mixture: 22.50%
Flow and surface regulating additive: 2.00%
Catalyst: 0.40%
Defoamer: 0.10%
Total: 100%
Application approach:
The OH value of the resin is determined.
The NCO content of polyisocyanate is taken into account.
A polyisocyanate level of 20% is the sample value for baseline screening and is validated against the actual NCO/OH ratio.
The components are mixed before application.
The initial viscosity is measured.
The duration of use is followed.
The standard panel is prepared.
Drying time is measured.
Hardness and adhesion are checked.
Chemical resistance is tested.
Impact or bending performance is examined.
Accelerated outdoor testing is applied.
Color and gloss preservation are compared.
ALTERNATIVES AND COMPARISONS OF ISOPHORONE DIISOCYANATE
When determining the alternative for Isophorone Diisocyanate, only the NCO content should not be considered. Molecular structure, light resistance, reaction rate, viscosity, hardness and final application should be evaluated together.
ISOPHORONE DIISOCYANATE AND HEXAMETHYLENE DIISOCYANATE (HDI)
HDI is a linear aliphatic diisocyanate. Isophorone Diisocyanate, on the other hand, has a cycloaliphatic structure with a cycloaliphatic.
Both products can be used in the preparation of low yellowing prone polyurethanes. However, the final rigid segment structures are different.
Isophorone Diisocyanate can stand out in terms of hardness and rigidity contribution. HDI can be preferred in the preparation of more flexible polyurethane structures.
In the coatings industry, it is possible to use IPDI and HDI-derived polyisocyanates together. This approach can help strike a balance between stiffness and flexibility.
No direct weight substitution. Calculation should be made on actual NCO equivalents.
ISOPHORONE DIISOCYANATE AND H12MDI
H12MDI is another cycloaliphatic diisocyanate. It shows different physical and reaction properties than Isophorone Diisocyanate due to its larger structure with two rings.
H12MDI can be used in high light resistant elastomer, thermoplastic polyurethane and special coating systems. Isophorone Diisocyanate can provide advantages in low viscosity and controlled prepolymer synthesis.
The equivalent weight and process conditions of the two products are different. The formulation should not be transferred directly.
ISOPHORONE DIISOCYANATE AND MDI
MDI is in the aromatic diisocyanate class. It has a wide range of uses in the production of foam, insulation, adhesives and elastomers.
MDI can often provide higher reactivity and economic advantage. However, the aromatic structure increases its tendency to yellow under light.
Isophorone Diisocyanate can be preferred especially in transparent or light-colored applications where color and appearance preservation are important.
Two products cannot be used directly at the same weight. NCO equivalent calculation and process conditions should be redetermined.
ISOPHORONE DIISOCYANATE AND TDI
TDI is an aromatic and more volatile diisocyanate. It is widely used in the production of flexible polyurethane foam.
Isophorone Diisocyanate has lower volatility and cycloaliphatic structure. Therefore, its uses are greatly different.
TDI can provide faster reactions, while Isophorone Diisocyanate is advantageous in terms of controlled synthesis and light resistance.
Direct weight substitution is not appropriate.
ISOPHORONE DIISOCYANATE AND IPDI TRIMER
Monomeric Isophorone Diisocyanate and IPDI trimer are not the same product. Monomeric product is a bifunctional starting raw material.
The IPDI trimer is prepared by combining monomers in isocyanurate structure. It shows higher functionality and can be used as a crosslinker.
IPDI trimer or other low monomer polyisocyanates can be used in two-component polyurethane paints. Monomeric Isophorone Diisocyanate is mostly the synthesis raw material of these products.
Therefore, trimer and monomer cannot be used directly interchangeably.
ISOPHORONE DIISOCYANATE AND BLOCKED IPDI
In blocked IPDI derivatives, NCO functions are temporarily passivated. In this way, more stable single-component systems can be prepared.
At the appropriate oven temperature, cross-linking becomes active. This property can be used in heat-curing coatings.
Monomeric Isophorone Diisocyanate does not exhibit the same storage behavior as it carries free NCO.
QUALITY CONTROL AND PURCHASING CRITERIA FOR ISOPHORONE DIISOCYANATE
When purchasing Isophorone Diisocyanate, the product name and price alone are not sufficient. Parameters such as NCO content, purity, color, and chlorine level can influence the consistency of subsequent reactions.
Recommended information to review before purchasing:
Product name and manufacturer
Chemical Identity
CAS number
EC/EINECS number
Whether it is a monomeric product or not
Purity
NCO content
NCO equivalent weight
Total chlorine
Hydrolysis can chlorine
Color value
Viscosity
Density
Refractive index
Humidity specification, if applicable
Storage conditions
Shelf life
Packaging Type
Net quantity
Batch number
Production date
Information of origin
TDS
SDS
COA
REACH information
Educational information on the use of diisocyanate
The COA shows the actual analysis results for the specific batch. In particular, the NCO content can be used directly in the sensitive prescription account.
TDS describes the standard technical specifications and general uses of the product. SDS contains safe handling, exposure, storage and emergency information.
Color value can be important in clear coatings. If the starting raw material is high colored, it can affect the final resin color.
Total chlorine or hydrolysis can be chlorine can be controlled separately in some sensitive polyurethane syntheses. These parameters may become important, especially in terms of catalyst system and final product purity.
When switching to a new supplier, it may be useful to perform a comparative laboratory reaction. The reaction rate, viscosity, color and amount of monomer remaining can be compared.
STORAGE AND HANDLING OF ISOPHORONE DIISOCYANATE
Storage: Isophorone Diisocyanate should be stored in dry, tightly sealed, and chemically appropriate packaging. The manufacturer's recommended temperature range and storage conditions should be maintained.
Protection from moisture: Tanks, pumps, hoses and piping systems must be dry as water reacts with NCO groups. Opened packages should be resealed to reduce moisture ingress.
Transfer and handling: Closed transfer systems can help both maintain product quality and reduce worker exposure. Splashing and aerosol formation should be avoided as much as possible.
Incompatible substances: Uncontrolled contact with water, alcohols, amines, and other active hydrogen-containing compounds should be avoided. Other incompatible substances specified in the current SDS should also be considered.
Shelf life: The current Evonik technical information specifies a storage period of at least one year for VESTANAT IPDI stored in sealed packaging under appropriate conditions. Longer storage may result in an increase in color value.
Transportation: The current transportation classification for Isophorone Diisocyanate must be verified from the SDS document of the purchased product. NIOSH lists the DOT ID 2290 information for the substance.
ISOPHORONE DIISOCYANATE SAFETY INFORMATION
Isophorone Diisocyanate is a reactive diisocyanate and its safe use should be based on current SDS.
NIOSH specifies an 8-hour recommended exposure limit of 0.005 ppm and a short-term exposure limit of 0.02 ppm for Isophorone Diisocyanate; skin notation is also available.
Isophorone Diisocyanate is an important chemical for skin and respiratory sensitization. Adequate ventilation, closed process, appropriate gloves, eye and face protection and appropriate respiratory protection should be used when necessary.
Low vapour pressure does not mean that there is no exposure in spraying or aerosol-forming processes. These processes should also be subject to risk assessment.
It should not be assumed that the safety profiles of monomeric Isophorone Diisocyanate and the low monomer polyisocyanates derived from it are the same. The SDS document of each product should be reviewed separately.
WHAT TO CONSIDER WHEN BUYING ISOPHORONE DIISOCYANATE?
The first step in the supply of Isophorone Diisocyanate is to determine which polyurethane system the product will be used in. Different quality parameters may come to the fore in the production of prepolymer, polyurethane dispersion, urethane acrylate, trimer or elastomer.
Making it clear at the time of ordering that monomeric Isophorone Diisocyanate is requested instead of just "IPDI" makes it easier to evaluate the right product.
The following information should be clarified before purchasing:
Use sector and end application
Monomeric product requirement
Minimum desired purity
Desired NCO content
Total chlorine limit
Hydrolysis can chlorine limit
Color limit
Viscosity range
Density value
Humidity limit, if any
Manufacturer preference
Preference for origin
Packing quantity
Shelf life
Storage conditions
The need for TDS
The need for SDS
The need for COA
REACH documents
Regulatory information on the use of diisocyanates
If substitution is to be made with the existing product, the existing TDS and COA
The price of Isophorone Diisocyanate may vary depending on the purity of the product, manufacturer, origin, chlorine specification, order quantity, packaging and logistics conditions. Technically, it may not be correct to compare different quality classes only on the kilogram price.
ISOPHORONE DIISOCYANATE SUPPLY FROM ATAMAN KIMYA
Isophorone Diisocyanate; It is a cycloaliphatic diisocyanate used in the production of polyurethane resins, coatings, adhesives, sealants, elastomers, leather and textile systems, and special polyisocyanates. It is important for companies planning to purchase the product to clarify the technical specifications suitable for the usage area before ordering.
Companies that want to get information about the supply of Isophorone Diisocyanate from Ataman Kimya can request information about product suitability, current supply conditions, packaging options and price offer by sharing their usage areas and target technical specifications.
The current stock status, manufacturer, origin, quality class, purity, NCO content, packaging and other technical specifications of the product should be confirmed from Ataman Kimya before ordering.
Sharing the following information in the request for quotation makes it easier to evaluate the right Isophorone Diisocyanate product:
Use sector and end application
Monomeric product need
Type of polyurethane to be produced
Minimum purity requested
Requested NCO content
Total chlorine requirement
Hydrolysis can chlorine requirement
Color requirement
Viscosity requirement
Polyol or resin system used
Estimated order quantity
Type of packaging requested
Requested technical documents
TDS or COA information of the current product, if applicable
FREQUENTLY ASKED QUESTIONS ABOUT ISOPHORONE DIISOCYANATE
What is Isophorone Diisocyanate?
Isophorone Diisocyanate is a cycloaliphatic diisocyanate carrying two reactive NCO groups. It can be used in the production of polyurethane resins, coatings, adhesives, elastomers, and waterborne polyurethane dispersions.
What is Isophorone Diisocyanate short for?
The most common abbreviation is IPDI.
What is the CAS number of Isophorone Diisocyanate?
CAS No is 4098-71-9.
What is the EC number of Isophorone Diisocyanate?
EC/EINECS No is 223-861-6.
What is the molecular formula of Isophorone Diisocyanate?
C₁₂H₁₈N₂O₂.
What is the molecular weight of Isophorone Diisocyanate?
It is approximately 222.28 g/mol.
How many NCO groups does Isophorone Diisocyanate contain?
It contains two isocyanate groups per molecule and has a nominal functionality of 2.
What is the NCO content of Isophorone Diisocyanate?
The theoretical NCO content is approximately 37.8%. In current high-purity commercial products, the range of approximately 37.5–37.8% can be seen.
What is the NCO equivalent weight of Isophorone Diisocyanate?
It is approximately 111.1 g/eq.
Is Isophorone Diisocyanate a liquid?
It is clear at room temperature, low viscosity, and usually colorless to slightly yellow liquid.
Why is Isophorone Diisocyanate used in the production of polyurethane?
NCO groups react with hydroxyl groups present in polyols to form urethane bonds and form polyurethane structure.
Do the two NCO groups of Isophorone Diisocyanate have the same reactivity?
Due to the asymmetric nature of the molecule, NCO groups can show different reactivity.
Why is Isophorone Diisocyanate used in systems where low yellowing is required?
Its cycloaliphatic structure provides a lower tendency to change color under light than aromatic MDI and TDI systems.
Are Isophorone Diisocyanate and HDI the same product?
HDI has a linear aliphatic structure and Isophorone Diisocyanate has a cycloaliphatic structure with a cycloaliphatic structure.
Are Isophorone Diisocyanate and H12MDI the same product?
Although both are cycloaliphatic diisocyanates, their molecular structures and physical properties are different.
What is the main difference between Isophorone Diisocyanate and MDI?
MDI is an aromatic, while Isophorone Diisocyanate is a cycloaliphatic diisocyanate. Isophorone Diisocyanate provides an advantage in systems where color and light stability are important.
What is Isophorone Diisocyanate trimer?
It is a higher functioning polyisocyanate obtained by combining IPDI molecules into an isocyanurate structure. It can be used as a hardener in two-component coatings.
Is monomeric Isophorone Diisocyanate the same as IPDI trimer?
Functionality, molecule size, NCO content and usage patterns are different.
What is blocked IPDI?
The NCO groups are temporarily reacted-sealed IPDI derivative and can be used in heat-cured single-component systems.
Is Isophorone Diisocyanate used in waterborne polyurethane dispersions?
It is one of the important raw materials for water-based polyurethane dispersions due to its low-viscosity prepolymer forming feature.
Is Isophorone Diisocyanate used in adhesives?
It can be used in waterborne polyurethanes, hot melt adhesives, and moisture-curing prepolymers.
Is Isophorone Diisocyanate used in sealants?
It can be evaluated in the preparation of NCO-tipped polyurethane and silane-terminated polyurethane resins.
Is Isophorone Diisocyanate used in the production of elastomers?
It can be used especially in polyurethane elastomers where light resistance and light color are important.
Is Isophorone Diisocyanate used in the production of urethane acrylate?
Radiation-cured urethane acrylates can be prepared by reacting with acrylates with hydroxyl function.
Does Isophorone Diisocyanate react with water?
During the reaction, carbon dioxide can be released and urea structures can form.
Why should Isophorone Diisocyanate be protected from moisture?
Moisture can deplete NCO groups, alter the chemical composition of the product, and cause gas to form.
What is the commercial purity of Isophorone Diisocyanate?
For current high-purity products, 99.5≥% purity is a common specification.
What is the viscosity of Isophorone Diisocyanate?
In a current high-purity product, it is given at approximately 13–15 mPa·s at 23 °C.
What is the density of Isophorone Diisocyanate?
It is about 1.058 g/cm³, with a value of 20 °C.
What is the flash point of Isophorone Diisocyanate?
In the current Evonik data, it is approximately 151 °C with the closed cup method.
What is the freezing point of Isophorone Diisocyanate?
It is around -60 °C.
Why is the chlorine content of Isophorone Diisocyanate important?
Chlorine-containing impurities may be important in some sensitive polyurethane syntheses in terms of reaction behavior, catalyst system, and color.
Is Isophorone Diisocyanate used in food applications?
It is not a direct food additive or flavoring agent.
Is Isophorone Diisocyanate used in cosmetics?
Monomeric Isophorone Diisocyanate is not a standard cosmetic raw material.
What features are important when buying Isophorone Diisocyanate?
NCO content, purity, color, chlorine, viscosity, density, and verifying that the product is monomeric IPDI are important criteria.
What documents should be required when purchasing Isophorone Diisocyanate?
TDS, SDS and COA are the basic documents. Depending on the application, REACH and other regulatory documents may also be requested.
How should Isophorone Diisocyanate be stored?
It should be stored in dry, tightly closed, compatible packaging and under the conditions recommended by the manufacturer, protected from moisture and reactive substances.
ISOPHORONE DIISOCYANATE – TECHNICAL SUMMARY
Isophorone Diisocyanate, known as Isophorone Diisocyanate in Turkish, is a bifunctional cycloaliphatic diisocyanate with the formula C₁₂H₁₈N₂O₂. The molecular weight of the product, defined by CAS No 4098-71-9 and EC No 223-861-6, is approximately 222.28 g/mol.
Isophorone Diisocyanate carries two reactive NCO groups, and the theoretical NCO content is about 37.8%. High-purity commercial products can see an NCO content of about 37.5–37.8% and a purity of at least 99.5%.
The presence of the two NCO groups in different steric environments gives Isophorone Diisocyanate selective reaction behavior. This property can be evaluated in processes where controlled propolymer synthesis and low levels of free monomers are targeted.
The cycloaliphatic structure helps Isophorone Diisocyanate-based polyurethanes to have a lower yellowing tendency than aromatic diisocyanate systems. Transparent coatings, automotive topcoats, light-colored polyurethanes, leather coatings and outdoor applications are therefore important areas of use.
Isophorone Diisocyanate; It can be used in the preparation of polyurethane coatings, water-based dispersions, adhesives, sealants, elastomers, urethane acrylates, moisture-curing prepolymers and silane-terminated polyurethanes.
Isophorone Diisocyanate is also the raw material of IPDI trimers and other high-functional polyisocyanates. These derivatives can be considered as crosslinkers, especially in two-component polyurethane coatings.
Current commercial product data can show a density of approximately 1.058 g/cm³, a viscosity of 13–15 mPa·s, a refractive index of 1.483, a solidification temperature of approximately -60 °C, and a closed-cup flash point of approximately 151 °C.
When purchasing the product, NCO content, purity, color, total chlorine, viscosity and batch COA values should be checked. Especially in sensitive polyurethane recipe calculations, using the actual NCO content provides more accurate results.
Since Isophorone Diisocyanate reacts with water, storage and process equipment should be kept dry. Current SDS should be used as a basis for safe use, exposure control, and selection of personal protective equipment.
It is recommended that companies planning to supply Isophorone Diisocyanate from Ataman Kimya confirm the current product and offer conditions by sharing the usage area, monomeric product requirement, minimum purity and NCO content, color and chlorine limits, packaging quantity and technical document needs.
