Quick Search
Pigment Yellow 181 is an inorganic pigment widely used in plastics, coatings, and inks due to its excellent heat stability, weather resistance, and opacity.
CAS No.: 74441-05-7
Synonyms
Benzimidazolone Yellow 181,Isoindoline Yellow,PY 181,C.I. Pigment Yellow 181,Irgazin Yellow 181 (BASF trade name),Hostaperm Yellow H4G (Clariant trade name),Sico Yellow 181,Paliotol Yellow L 1810 (BASF)
Pigment Yellow 194 (PY194) is a high-performance organic pigment widely used across various industries for its exceptional lightfastness, thermal stability, and vibrant color properties.
This document provides an in-depth scientific examination of PY194, encompassing its chemical identity, synthesis pathways, physicochemical characteristics, performance in diverse applications, and environmental and toxicological assessments.
Special attention is given to its role in sustainable formulations, regulatory status, and future development potential.
Introduction
Pigments are essential components in coloring materials used across industries such as plastics, coatings, inks, and textiles.
Among the vast array of yellow pigments, Pigment Yellow 194 has gained prominence due to its excellent performance characteristics.
This review consolidates detailed scientific insights into PY194, including its origin, classification, and importance in modern materials science.
Chemical Identity and Nomenclature
Chemical Name: Benzamide, 4-[2,4-dichloro-5-[(2-ethoxy-4-nitrophenyl)azo]phenylmethyl]-N-methyl-
C.I. Pigment Yellow 194
CAS Number: 61968-76-1
Chemical Class: Azo pigment (disazo-condensation type)
Molecular Formula: C22H18Cl2N4O5
Molecular Weight: ~489.31 g/mol
Molecular Structure and Physicochemical Properties
Structural Features: Disazo linkage with nitro and halogen substitutions contributing to electron delocalization.
Solubility: Insoluble in water; very low solubility in most organic solvents.
Melting Point: >300°C (decomposes)
Color Index Hue: Yellow to greenish-yellow
Specific Gravity: 1.5 - 1.8
Oil Absorption: Moderate
Synthesis Pathways
PY194 is synthesized through diazotization and coupling reactions involving chlorinated and nitrated aromatic amines.
A condensation reaction with a benzamide derivative completes the pigment formation.
The process involves:
Nitration of aromatic compound
Diazotization using nitrous acid
Coupling with ethoxy-substituted phenol
Formation of the azo bond
Final condensation with N-methyl benzamide
Characterization Techniques
FTIR Spectroscopy: Identifies functional groups
UV-Vis Spectrophotometry: Color strength and absorption maxima
XRD (X-ray Diffraction): Crystallinity
SEM/TEM: Particle morphology
TGA/DSC: Thermal behavior
Elemental Analysis: Confirm composition
Thermal and Chemical Stability
PY194 exhibits high thermal stability, tolerating processing temperatures up to 300°C without degradation.
It is resistant to acids, alkalis, and most solvents, making it suitable for demanding environments.
Optical and Colorimetric Properties
Hue Angle: ~95-100° in CIELAB color space
Tinting Strength: High
Opacity: Moderate to high depending on particle size
Lightfastness: Excellent (rating 7-8 on Blue Wool Scale)
Dispersibility and Particle Size Distribution
Controlled milling processes ensure narrow particle size distributions (~100-200 nm), enhancing gloss and color strength.
Surface treatments improve wetting and compatibility.
Application Fields
Automotive coatings
Industrial paints
Polyolefin plastics
Powder coatings
Printing inks (offset, gravure)
Textiles and synthetic fibers
Use in Plastics
PY194 is widely used in polyolefins, PVC, PET, and ABS due to its high heat resistance and migration resistance.
It retains color under extrusion and molding conditions.
Use in Coatings
Preferred in high-performance coatings, PY194 offers weather and UV resistance.
Used in automotive finishes and industrial applications requiring outdoor durability.
Use in Printing Inks
Inks formulated with PY194 exhibit excellent print quality, rub resistance, and compatibility with various printing methods, especially for packaging and labels.
Use in Textiles and Fibers
While less common than other applications, PY194 is utilized in coloring synthetic fibers such as polyester and nylon for high-end textile finishes.
SAFETY INFORMATION ABOUT PIGMENT YELLOW 181
First aid measures:
Description of first aid measures:
General advice:
Consult a physician.
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
If inhaled:
If breathed in, move person into fresh air.
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately.
Wash off with soap and plenty of water.
Consult a physician.
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
If swallowed:
Do NOT induce vomiting.
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
Consult a physician.
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment.
Avoid breathing vapours, mist or gas.
Evacuate personnel to safe areas.
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste.
Keep in suitable, closed containers for disposal.
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
Conditions for safe storage, including any incompatibilities:
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.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles.
Faceshield (8-inch minimum).
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Skin protection:
Handle with gloves.
Gloves must be inspected prior to use.
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product.
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices.
Wash and dry hands.
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls.
If the respirator is the sole means of protection, use a full-face supplied air respirator.
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions.
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company.
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product
