SYNOX GREEN 4590

This article provides an exhaustive review of SYNOX GREEN 4590, a commercially available complex green pigment used extensively in coatings, paints, plastics, construction materials, and printing inks. 
The manuscript covers identity and nomenclature, chemical composition and CAS references, synthesis and manufacture, physical and chemical properties, analytical characterization methods, applications and performance in formulations, compatibility and processing guidelines, environmental fate and management, regulatory status, quality control, and test methods relevant to industry users and researchers
Identity, Synonyms, and Registry Numbers
Trade name: SYNOX GREEN 4590
Common synonyms and identifiers (collected from commercial technical data and trade catalogues):
Synox Green 4590
Synox Vert 4590
Pigment Green 7 (in some blended formulations)
Phthalocyanine-based green complex pigment
Complex green pigment (organic + inorganic mixture)
Key component CAS / registry numbers associated with components commonly present in SYNOX GREEN 4590 blends:
Polychloro copper phthalocyanine (often listed under the broad name Pigment Green 7 / phthalocyanine green) — CAS: 1328-53-6 (polychloro copper phthalocyanine / Pigment Green 7).
Copper(II) phthalocyanine (parent phthalocyanine blue) — CAS: 147-14-8 (appears in literature for Cu-phthalocyanine derivatives).
Yellow iron oxide species (iron hydroxide oxide / Pigment Yellow 42 or similar iron oxide yellow components) — CAS: 51274-00-1 (iron hydroxide oxide, commonly used as yellow iron oxide in complex green formulations).
 
SYNOX GREEN 4590 is marketed as a complex pigment (organic + inorganic). 
Different suppliers may report the product as a formulated blend with varying proportions of copper phthalocyanine derivatives (phthalo greens/blends) and synthetic iron oxide yellow/iron-oxide components. 
As such, a single CAS number that unequivocally represents the finished commercial complex pigment may not always exist — manufacturers and distributors often list the CAS/EC numbers of the principal input pigments or the dominant constituent(s).
 
Chemical Nature and Composition
SYNOX GREEN 4590 is a complex green pigment produced by combining high-chroma organic phthalocyanine-type pigments (phthalocyanine green or chlorinated phthalocyanine derivatives) with inorganic iron-oxide type pigments (usually yellow iron oxide or synthetic iron oxide) to tune hue, opacity, lightfastness, weather resistance, and hiding power. 
These complex pigments are engineered to deliver the vividness and tinting strength of phthalocyanine greens while improving opacity and heat / weather resistance through the inclusion of iron oxide components.
 
Typical composition (qualitative)
Organic phthalocyanine fraction: provides chroma, tinting strength and chromatic purity. 
This fraction is based on copper phthalocyanine derivatives (often chlorinated or otherwise halogenated to shift hue towards green).
Inorganic iron oxide fraction (synthetic iron oxide yellow or Fe(OH)O/Fe2O3-related material): provides opacity, improves mass tone, optical density and lightfastness under harsh conditions, and increases thermal stability.
Minor additives / dispersing agents: surface treatments, small amounts of organic dispersants, anti-caking agents, or processing aids may be present depending on the supplier and grade.
Manufacturers typically specify a minimum iron-oxide content (for some grades, e.g., "minimum 50% Fe₂O₃ equivalent by pigment weight") to ensure consistent performance in coating systems.
 
Synthesis and Manufacturing Routes
Because SYNOX GREEN 4590 is a formulated product (a complex pigment), its manufacture involves: (1) production or procurement of the individual pigment components, and (2) controlled blending and milling to achieve the desired particle size distribution and shade.
 
(A) Production of phthalocyanine green derivatives
Base chemistry: copper phthalocyanine (CuPc) is synthesized by high-temperature cyclotetramerization of phthalonitrile or phthalic anhydride derivatives in the presence of copper salts. Chlorination (to produce polychloro CuPc derivatives) is typically conducted on the CuPc core or during synthesis to produce various chlorinated grades (these shift hue toward green and improve fastness in some cases).
Purification: washing, filtration and drying of the crystalline pigment; optional sublimation or re-precipitation for high-purity applications.
Particle engineering: micronization and surface treatment (with organic or inorganic coatings) optimize dispersibility and interaction with formulation resins.
(B) Production of synthetic iron oxide yellow / iron hydroxide-oxide
Routes: synthetic iron oxides (including yellow iron oxide / iron hydroxide oxide) are prepared by controlled precipitation of iron salts (Fe(II)/Fe(III)) followed by oxidation and heat treatment to achieve the desired phase (Fe₂O₃·H₂O or related stoichiometries), roasting or calcination steps to convert to stable oxide phases, then comminution to target particle sizes.
 
(C) Blending and complex pigment formation
Mixing: measured proportions of organic and inorganic pigment powders are dry-blended or wet-milled together. 
Milling (ball milling, bead milling, or high-shear dispersion) is used to reach a target particle size distribution and to intimately disperse the phases.
Surface treatments: the finished complex pigment may be coated to improve hydrophilicity/hydrophobicity or to impart anti-settling characteristics for specific applications.
Quality checks: colorimetry, particle size analysis, oil absorption, moisture content and sieve residue are routine QC tests before packaging.
 
Physical and Chemical Properties
Properties can vary by supplier/grade; typical values for a Synox-style complex green pigment are summarized below (example ranges based on commercial technical data):
Appearance: fine powder; bright green to deep green depending on formulation.
Solubility: insoluble in water and most organic solvents (dispersible as pigment particles).
Particle size: typically engineered between 0.02–5 μm (median sizes often in sub-micron to low micron range depending on milling).
Moisture: typically ≤ 1–2% (grade dependent).
pH (aqueous slurry): approx. 4–8.
Oil absorption: 20–60 g/100 g pigment (influences formulation rheology).
Bulk / apparent density: 0.6–1.2 g/cm³ (dependent on porosity and surface treatment).
Thermal stability: organic fraction (phthalocyanine) is normally stable to several hundred °C in inert atmospheres; combined complex pigments typically withstand typical baking/processing temperatures used in coatings and plastics but should be checked for extreme high-temperature applications.
Lightfastness & weathering: phthalocyanine greens generally have excellent lightfastness; combined with inorganic iron oxide the complex pigment offers superior weathering, reduced fading and improved heat/migration resistance compared to pure organic greens.
 
Analytical Characterization Methods
A rigorous analytical program is used to confirm identity and ensure consistent performance:
Colorimetry / Spectrophotometry (CIELAB): measure hue, chroma and lightness; used for quality control and shade matching.
Particle size distribution: laser diffraction or electron microscopy to ensure dispersion and tinting behavior.
X-ray diffraction (XRD): to identify crystalline phases (especially iron oxide components).
Fourier-transform infrared spectroscopy (FTIR): to verify organic functional groups and surface treatments.
Thermogravimetric analysis (TGA) / Differential scanning calorimetry (DSC): to study thermal stability and composition ratios.
Inductively coupled plasma optical emission spectroscopy (ICP-OES) or atomic absorption spectroscopy (AAS): to quantify metallic elements (e.g., Cu, Fe) and trace metals.
Elemental CHN analysis: to verify organic content and degree of chlorination in chlorinated phthalocyanines.
Moisture and volatile content: Karl Fischer titration or gravimetric drying.
Oil absorption (ASTM methods): impacts formulation rheology.

SAFETY INFORMATION ABOUT SYNOX GREEN 4590

 
 
 
 
 
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