ARADUR 423 XW 60

ARADUR 423 XW 60 is a solvent-borne polyamidoamine-adduct epoxy curing agent developed for cold-curing protective coatings, anti-corrosion primers and marine finishes where improved humidity tolerance, low surface tack and good flow are required. The commercial grade is supplied at approximately 59-61% solids in a xylene/n-butanol solvent blend at an approximate 4:1 ratio and combines the adhesion and flexibility associated with polyamidoamine chemistry with the more controlled cure behavior produced by pre-adduct modification. ARADUR 423 XW 60 is particularly useful in solvent-containing coatings for steel and mineral substrates where tack-free cure must be maintained at relative atmospheric humidity levels up to approximately 80%, making it especially relevant to shipbuilding, construction and industrial maintenance applications.

PRODUCT IDENTITY

Product name: ARADUR 423 XW 60
Product type: Epoxy curing agent / hardener
Chemical family: Polyamides / polyamidoamines
Specific chemistry: Polyamidoamine adduct
Carrier solvents: Xylene and n-butanol
Approximate solvent blend ratio: Xylene/n-butanol 4:1
Physical form: Liquid
Appearance: Clear yellow to brown liquid
Color: Gardner ≤10
Odor: Xylene / n-butanol / amine
Solids content: Approximately 59-61%
Viscosity at 25°C: Approximately 800-1,400 mPa·s
Amine value: Approximately 122-138 mg KOH/g
Active hydrogen equivalent weight: Approximately 520 g/eq
Density at 20°C: Approximately 0.94 g/cm³
Flash point: Approximately 28°C by Pensky-Martens closed-cup testing
Comparative selector gel time: Greater than approximately 1,000 minutes with the referenced solid epoxy resin and solvent comparison system
Typical selector mix ratio: Approximately 110 g hardener per 100 g of the referenced resin system
Reference mix ratio with ARALDITE GZ 7071 X 75: Approximately 100:82 parts by weight resin to hardener
Mix-ratio adjustment in the reference system: Up to approximately ±15% depending on target properties
Higher hardener proportion: Tends to increase flexibility and adhesion
Lower hardener proportion: Tends to improve chemical resistance
Relative-humidity capability: Tack-free cure up to approximately 80% relative atmospheric humidity
Primary functions: Curing agent, hardener and crosslinker
Primary end uses: Anti-corrosion coating, cold-curing coating, marine finish and solvent-borne coating
Primary substrates: Steel and mineral substrates
Primary sectors: Shipbuilding, anti-corrosion protection, construction and industrial maintenance
Key technical features: Humidity resistance, improved flow, low tack and tack-free cure
Resin compatibility: Liquid epoxy resins, preferably solid epoxy resins, and epoxy-resin solutions
Reference resin system: ARALDITE GZ 7071 X 75
Comparative family relationship: ARADUR 423 XW 60 lies between ARADUR 422 XW 70 and ARADUR 424 XW 50 in solids, viscosity, reactivity and humidity tolerance
Humidity comparison: Higher humidity tolerance than ARADUR 422 XW 70 and lower humidity tolerance than ARADUR 424 XW 50
Solids comparison: Lower solids than ARADUR 422 XW 70 and higher solids than ARADUR 424 XW 50
Storage range: Approximately 2-40°C in sealed original packaging
Storage condition: Dry place, sealed original container and protection from direct sunlight
CAS Number: Commercial polyamidoamine-adduct solution; no single CAS number should be assigned to the complete trade grade without the current SDS
EC Number: Commercial mixture; no single EC number should be assigned to the complete trade grade without the current SDS
Molecular Formula: Not applicable to the complete commercial mixture
Molecular Weight: Variable / not applicable as one fixed molecular weight

ARADUR 423 XW 60 should be treated as a formulated commercial polyamidoamine-adduct hardener rather than as one pure chemical substance. The product contains a reactive polymeric curing-agent fraction together with xylene and n-butanol, so one molecular formula or molecular weight cannot accurately represent the commercial grade. Formal component identity, concentration ranges, hazard classification, transport data and occupational-control requirements should therefore be taken from the current product-specific SDS.

WHAT IS ARADUR 423 XW 60?

ARADUR 423 XW 60 is a pre-adducted polyamidoamine curing agent designed for solvent-containing epoxy coatings that need reliable ambient cure under cooler and more humid conditions than many conventional polyamidoamine systems can tolerate.
The active curing-agent chemistry has undergone a controlled pre-reaction before the product is supplied. This pre-adduct structure improves surface cure, reduces tackiness and increases resistance to atmospheric humidity.
The grade is supplied at approximately 60% solids in a xylene/n-butanol solvent blend at an approximate 4:1 ratio. The lower viscosity of approximately 800-1,400 mPa·s makes ARADUR 423 XW 60 much easier to pump, meter and disperse than more concentrated polyamidoamine-adduct solutions.
The product is especially useful in steel and mineral coatings used in shipbuilding, anti-corrosion protection, construction and industrial maintenance.
Its approximately 80% relative-humidity capability places ARADUR 423 XW 60 between ARADUR 422 XW 70 and ARADUR 424 XW 50 in the cold-damp curing family.

POLYAMIDOAMINE ADDUCT CHEMISTRY

Polyamidoamines contain both amide structures and reactive amine functionality. Their molecular architecture is associated with strong adhesion, flexibility, toughness and relatively forgiving cure behavior in epoxy systems.
A polyamidoamine adduct is produced by partially reacting the starting amine-functional material with epoxy functionality before the hardener reaches the final user. This increases molecular size and changes the distribution of free amine groups.
Pre-adduction can improve compatibility with epoxy resin, reduce surface tack and improve cure under humid or cool environmental conditions.
The chemistry also removes the need for a separate pre-reaction or aging stage that might otherwise be required to obtain comparable surface performance from a non-adducted hardener.
ARADUR 423 XW 60 therefore combines traditional polyamidoamine flexibility and adhesion with enhanced ambient-cure reliability.

HOW EPOXY CURING WORKS

Epoxy resins contain reactive oxirane rings. Primary and secondary amine hydrogens in ARADUR 423 XW 60 attack these rings and open them, forming carbon-nitrogen bonds and hydroxyl groups.
Because both the epoxy resin and hardener contain multiple reactive sites, repeated reaction creates a three-dimensional thermoset network.
The mixed coating initially remains fluid, then gradually increases in molecular weight and viscosity until gelation occurs. Crosslinking continues after gelation and after the film first becomes tack-free.
The xylene/n-butanol carrier does not form the main polymer network. These solvents must evaporate from the coating while cure proceeds.
Final mechanical strength, chemical resistance, adhesion and corrosion resistance therefore depend on both solvent release and chemical crosslinking.

PRE-ADDUCT TECHNOLOGY

Pre-adduct technology is one of the defining features of ARADUR 423 XW 60.
Conventional polyamidoamine hardeners can sometimes require a pre-reaction with epoxy resin to improve surface cure or resistance to humid conditions.
ARADUR 423 XW 60 already contains a controlled degree of prior reaction, so the intended hardener behavior is built into the commercial product.
This reduces processing time, simplifies formulation and improves reproducibility.
The pre-adduct structure also contributes to lower tack, improved flow and broader humidity tolerance.
Because the degree of adduction is controlled during manufacture, the curing agent can deliver more consistent coating behavior than a field-prepared pre-reaction mixture.

SOLIDS CONTENT

ARADUR 423 XW 60 contains approximately 59-61% solids.
The remaining fraction consists mainly of xylene and n-butanol used to maintain a manageable viscosity and support film formation.
Solids content determines how much active hardener is delivered by a given wet weight of commercial material.
If solids decrease, more solvent and less reactive curing-agent material are introduced at the same weight.
If solids increase, active concentration and viscosity can rise.
The approximately 60% solids level therefore forms an important part of both stoichiometric calculation and quality control.

XYLENE AND N-BUTANOL SOLVENT SYSTEM

ARADUR 423 XW 60 is supplied in xylene/n-butanol at an approximate 4:1 ratio.
Xylene provides strong solvency for hydrophobic epoxy and polyamidoamine structures and helps reduce the viscosity of the active polymeric hardener.
n-Butanol provides additional polarity and can improve compatibility between amine-rich curing-agent chemistry and epoxy-resin solutions.
The combined solvent system influences viscosity, flow, evaporation rate and final film formation.
The 4:1 ratio contains a higher proportion of xylene relative to n-butanol than ARADUR 422 XW 70.
Because both solvents are volatile and flammable, ventilation, ignition control and appropriate PPE are necessary during storage, mixing and application.

VISCOSITY

ARADUR 423 XW 60 has a viscosity of approximately 800-1,400 mPa·s at 25°C.
This relatively low viscosity is a major practical advantage compared with higher-viscosity polyamidoamine-adduct solutions.
Low viscosity improves pumping, metering, blending and pigment dispersion.
It can also reduce the amount of additional solvent needed to reach spray or roller viscosity.
Temperature still affects viscosity significantly. Cold material becomes thicker, while warmer material becomes more fluid.
Quality-control comparison should therefore be made at the specified test temperature.

AMINE VALUE

The published amine value of ARADUR 423 XW 60 is approximately 122-138 mg KOH/g.
Amine value is a titration-based measure of total basic amine functionality expressed as equivalent potassium hydroxide.
This value is useful for batch consistency and product identity.
A substantial deviation can indicate concentration drift, contamination or chemical alteration.
Amine value should not be used alone to calculate stoichiometry because basic nitrogen and active amine hydrogen are not identical measures.
AHEW and resin-specific mix ratios are more directly useful for epoxy formulation.

ACTIVE HYDROGEN EQUIVALENT WEIGHT

ARADUR 423 XW 60 has an active-hydrogen equivalent weight of approximately 520 g/eq as supplied.
This relatively high AHEW reflects both the polymeric pre-adduct structure and the approximately 40% solvent fraction.
AHEW represents the mass of commercial hardener required to provide one equivalent of reactive amine hydrogen.
It is the key hardener parameter used with epoxy equivalent weight to estimate stoichiometric mix ratio.
Published resin-specific formulation data should still take priority when available because the resin may also be supplied in solvent and can have a specific solids content and EEW.

DENSITY

The typical density of ARADUR 423 XW 60 is approximately 0.94 g/cm³ at 20°C.
Density is useful for manufacturing calculations and conversion between weight and volume.
Weight-based dosing remains preferable for stoichiometric accuracy.
Volumetric dispensing systems should be calibrated using actual component density and temperature.
Density can also serve as a secondary quality-control parameter when evaluated together with solids, viscosity and amine value.

FLASH POINT AND FLAMMABILITY

ARADUR 423 XW 60 has a typical flash point of approximately 28°C by Pensky-Martens closed-cup testing.
This relatively low flash point results from the xylene/n-butanol solvent package.
The product should therefore be treated as a flammable solvent-containing industrial chemical.
Ignition sources, sparks, hot surfaces and static discharge should be controlled.
Ventilation is essential because solvent vapors can accumulate in enclosed spaces.
Firefighting procedures and storage segregation should follow the current SDS and local flammable-liquid requirements.

COLOR AND APPEARANCE

The normal appearance is a clear yellow-to-brown liquid with Gardner color no higher than approximately 10.
This color range is characteristic of the commercial grade and should not automatically be interpreted as deterioration.
Small color differences can occur in polymeric amine products without meaningful performance loss when all specification values remain within range.
Unexpected turbidity, sediment, phase separation or major viscosity change should be investigated.
Color is generally less critical in anti-corrosion and marine primers than in clear or pale decorative coatings.

HUMIDITY RESISTANCE

ARADUR 423 XW 60 is designed to tolerate relative atmospheric humidity up to approximately 80%.
This represents a significant advantage in shipbuilding, construction and maintenance work where ideal dry conditions cannot always be achieved.
Amine-cured epoxy systems can develop tack, haze, whitening or carbamate-related surface defects when curing under humid air.
The pre-adduct structure improves resistance to these surface problems.
The approximately 80% humidity capability is greater than the roughly 70% level associated with ARADUR 422 XW 70.
Humidity tolerance does not eliminate the need for dew-point control. Condensation on the substrate can still cause adhesion failure and surface defects.

TACK-FREE CURE

Tack-free cure is a principal performance feature of ARADUR 423 XW 60.
Persistent tack can attract dirt, delay handling and interfere with recoating.
The pre-adducted chemistry is designed to reduce this surface tack, particularly under cold-damp conditions.
Tack-free cure can be achieved at relative atmospheric humidity up to approximately 80% when other application conditions are appropriate.
Actual tack-free time depends on resin type, temperature, film thickness, solvent balance, ventilation and pigment loading.
A tack-free surface should not be mistaken for full chemical cure, which continues afterward.

LOW TACK

Low tack improves both coating quality and handling efficiency.
A less tacky surface collects less dust and contamination.
Coated components can move through production or maintenance schedules more reliably.
Low tack also reduces the likelihood of marking during handling and can improve the consistency of later overcoating.
The benefit arises from the pre-adducted chemistry rather than simply from very high cure speed.
This distinction is important because excessively fast cure can reduce flow and working time, while ARADUR 423 XW 60 maintains a more balanced ambient-cure profile.

IMPROVED FLOW

Improved flow is another key characteristic.
Good flow allows the wet film to redistribute after spray, brush or roller application and reduces local texture.
The relatively low viscosity of ARADUR 423 XW 60 contributes to this behavior.
The xylene/n-butanol solvent blend also provides a controlled evaporation profile that allows the film to level before complete set.
Uniform flow improves appearance and helps avoid excessively thin areas that could weaken corrosion protection.
Rheology modifiers should therefore be used carefully so that sag resistance is achieved without eliminating leveling.

COLD-CURE PERFORMANCE

ARADUR 423 XW 60 is intended for cold-curing solvent-borne epoxy coatings.
Cool conditions normally increase coating viscosity and reduce epoxy-amine reaction rate.
The pre-adduct structure improves surface cure and tack-free performance under these conditions.
Cold-cure capability is especially valuable in shipyards, construction sites and industrial maintenance where substrate temperature cannot always be maintained near laboratory conditions.
Minimum application temperature should still be validated for the complete coating system.
Substrate temperature should also remain safely above the dew point.

APPLICATIONS

Anti-corrosion coatings
Anti-corrosion coatings are a primary application for ARADUR 423 XW 60. The hardener supports durable epoxy barrier films with strong adhesion, low tack and broad humidity tolerance. Final corrosion resistance depends on the complete resin, pigment and film system.

Cold-curing coatings
ARADUR 423 XW 60 is specifically intended for cold-curing solvent-containing coatings. The pre-adduct structure supports more reliable surface cure when ambient temperature is reduced.

Marine finishes
Marine finishes are a listed end-use category. Ship and offshore steel coatings benefit from humidity tolerance, flow and strong epoxy adhesion when substrate preparation and salt removal are controlled.

Shipbuilding coatings
Shipbuilding is a core application sector. Fabricated steel frequently requires protective primer and intermediate systems that cure under variable temperature and humidity conditions.

Marine maintenance coatings
Maintenance of ships and marine structures can use ARADUR 423 XW 60 systems where cold-damp cure performance is important.

Steel primers
Prepared steel can be primed with compatible solvent-borne epoxy systems based on ARADUR 423 XW 60.

Structural-steel coatings
Bridges, factories, warehouses and industrial steel structures can use compatible protective primer systems.

Industrial maintenance coatings
Maintenance work in industrial facilities can benefit from the product's low viscosity and humidity tolerance.

Construction coatings
Construction is an important application area. Steel, concrete and other mineral substrates can use compatible solvent-borne epoxy technology.

Mineral-substrate coatings
ARADUR 423 XW 60 can be used with suitable epoxy-resin systems for mineral surfaces where solvent-containing coatings are appropriate.

Concrete primers
Solvent-borne epoxy primers can penetrate prepared concrete and provide a bonded base for protective layers.

Concrete sealers
Selected clear or pigmented sealers can use the hardener where substrate moisture and ventilation are appropriate.

Protective concrete coatings
Industrial concrete can be protected against water, oils and selected chemicals using a compatible fully cured epoxy system.

Factory-applied metal coatings
Controlled factory environments can provide consistent temperature and solvent extraction for ARADUR 423 XW 60 applications.

Machinery primers
Machine frames, housings and fabricated equipment can use compatible solvent-borne epoxy primers.

Equipment coatings
Industrial equipment exposed to moisture, salts or chemicals can use suitable protective coatings after resistance testing.

Pipe coatings
Prepared steel pipes can use ARADUR 423 XW 60-based primers for atmospheric and selected industrial exposure.

Tank exteriors
Exterior tank surfaces can use epoxy primers cured with ARADUR 423 XW 60 beneath suitable weather-resistant topcoats.

Coastal infrastructure
Steel near coastal environments can benefit from humidity-tolerant epoxy primers when chloride contamination is removed before coating.

Bridge-maintenance coatings
Protective maintenance systems for bridge steel can use ARADUR 423 XW 60 where solvent-containing coatings are permitted.

Port and harbor structures
Steel exposed to marine atmosphere can use heavy-duty epoxy primer systems based on this curing agent.

Marine equipment coatings
Deck machinery, supports and auxiliary steel components can use compatible ARADUR 423 XW 60 coatings.

Zinc primers
The hardener can be used in compatible zinc-containing anti-corrosion primers after zinc loading, stability and gas evolution have been validated.

Zinc-rich epoxy primers
Metallic-zinc formulations can provide sacrificial protection when sufficient zinc particle contact is maintained. Binder level and rheology must be 
optimized carefully.

Zinc-phosphate primers
Zinc phosphate and related inhibitive pigments can supplement epoxy barrier protection.

High-build primers
Solid epoxy-resin solutions can be combined with ARADUR 423 XW 60 to produce higher-build primer systems.

Barrier coatings
Lamellar fillers and extenders can be used to increase the diffusion path for moisture and oxygen.

Intermediate coats
ARADUR 423 XW 60 can be used in epoxy intermediate layers that build thickness beneath a weather-resistant finish coat.

Primer-sealers
Low-build primer-sealers can use the grade where penetration, adhesion and surface consolidation are needed.

Maintenance mastics
Filled solvent-borne mastics can use ARADUR 423 XW 60 where thixotropy and working time are controlled.

Industrial floor primers
Concrete flooring systems can use compatible solvent-borne primer technology where ventilation and solvent use are acceptable.

Repair coatings
Localized industrial coating repair can benefit from the product's cold-damp cure capability.

Marine repair coatings
Marine repair systems can use compatible formulations after salts, corrosion and weak old coating are removed.

Protective shop primers
Fabrication shops can use solvent-borne epoxy primers where reliable handling and tack-free cure are required.

Heavy-duty maintenance primers
The grade is suitable for robust maintenance systems requiring the adhesion and flexibility of polyamidoamine chemistry with improved humidity tolerance.

Chemical-resistant coatings
Lower hardener proportions within a validated formulation window can favor chemical resistance in the reference resin system.

Flexible protective coatings
Higher hardener levels within a validated range can favor flexibility and adhesion.

Adhesion-promoting primers
The pre-adducted polyamidoamine structure provides strong substrate bonding and can be used in primer layers beneath compatible coating systems.

Protective coatings for fabricated steel
Newly fabricated beams, frames and components can receive ARADUR 423 XW 60-based primer systems after proper preparation.

Warehouse steel coatings
Indoor structural steel can use solvent-borne epoxy coatings where ventilation and fire-safety controls are available.

Process-plant coatings
Industrial process facilities can use compatible epoxy primers on steel exposed to moisture, oils and selected chemicals.

Utility-area coatings
Mechanical rooms, service areas and industrial utility structures can use the grade where solvent-borne epoxy technology is appropriate.

Construction-steel primers
Beams, columns and fabricated structural members can use ARADUR 423 XW 60 primer technology.

Concrete repair primers
Solvent-borne epoxy primer systems can be used beneath compatible concrete repair materials where substrate moisture remains within system limits.

Mineral bonding layers
Compatible ARADUR 423 XW 60 epoxy systems can create adhesion-promoting layers between prepared mineral surfaces and later epoxy materials.

General protective coatings
Other industrial protective uses are possible when resin compatibility, solvent balance, environmental conditions and service exposure are validated.

ARALDITE GZ 7071 X 75 REFERENCE SYSTEM

ARADUR 423 XW 60 is specifically suited to ARALDITE GZ 7071 X 75 solid epoxy-resin solution technology.
The reference mix ratio is approximately 100 parts ARALDITE GZ 7071 X 75 to 82 parts ARADUR 423 XW 60 by weight.
This ratio reflects the commercial resin and hardener forms and should not be transferred directly to another resin with a different epoxy equivalent weight or solids content.
The combination is suitable for cold-curing solvent-containing coatings applied to steel and mineral substrates.
Shipbuilding, anti-corrosion protection and construction are important application areas for this resin-hardener approach.
The coating should still be optimized for pigment loading, solvent balance, film thickness and target dry time.

MIX-RATIO FLEXIBILITY

The reference ARALDITE GZ 7071 X 75 / ARADUR 423 XW 60 ratio can be varied by approximately ±15% depending on target coating properties.
Increasing the hardener proportion generally improves flexibility and adhesion.
Reducing the hardener proportion generally improves chemical resistance.
The change results from altered network stoichiometry and the balance between residual epoxy and amine functionality.
This range should be used intentionally as a formulation tool rather than treated as an allowance for inaccurate metering.
Each adjusted ratio should be tested for cure speed, tack-free time, hardness, adhesion, chemical resistance and corrosion performance.

SELECTOR REFERENCE RATIO

Comparative selector literature gives a typical mix ratio of approximately 110 parts ARADUR 423 XW 60 per 100 parts of the reference resin system used in that selector.
This figure differs from the approximately 100:82 ratio with ARALDITE GZ 7071 X 75 because the selector and product-specific resin systems are different.
Different resin epoxy equivalent weights, solids contents and solvent levels require different hardener quantities.
Both values can therefore be technically correct within their own formulation contexts.
The exact resin-specific technical recommendation should always take precedence over a generic selector value.

COMPATIBILITY WITH LIQUID EPOXY RESINS

ARADUR 423 XW 60 can be used with compatible liquid epoxy resins.
Liquid resins can lower overall binder viscosity and improve wetting.
The appropriate hardener amount depends on the actual epoxy equivalent weight of the resin.
The solvent balance may also need adjustment because the hardener already introduces xylene and n-butanol.
Final coating performance should be validated for pot life, dry time, flow, adhesion and chemical resistance.

PREFERENCE FOR SOLID EPOXY RESINS

Technical guidance identifies solid epoxy resins or their solutions as particularly suitable partners.
Solid epoxy resins generally have higher molecular weight and can provide strong film formation, toughness and protective performance in solvent-borne coatings.
Dissolving the solid resin in an appropriate solvent system allows processing and application while retaining the benefits of higher molecular weight.
ARADUR 423 XW 60 is well matched to this type of solvent-containing coating architecture.
The final solvent blend should remain compatible and should provide adequate flow without excessive VOC or slow drying.

COMPARISON WITH ARADUR 422 XW 70

ARADUR 423 XW 60 contains approximately 59-61% solids, compared with approximately 69-71% for ARADUR 422 XW 70.
ARADUR 423 XW 60 has much lower viscosity, approximately 800-1,400 mPa·s versus roughly 6,000-12,000 mPa·s.
Its AHEW is higher, approximately 520 g/eq versus about 340 g/eq.
The lower concentration means more wet hardener is required for the same epoxy functionality.
ARADUR 423 XW 60 provides broader humidity tolerance, reaching approximately 80% relative humidity rather than around 70%.
These differences make ARADUR 423 XW 60 attractive where easier handling and higher humidity tolerance are more important than maximum solids.

COMPARISON WITH ARADUR 424 XW 50

ARADUR 424 XW 50 is a still more dilute member of the same pre-adducted polyamidoamine family.
ARADUR 424 XW 50 is approximately 49-51% solids and has a higher AHEW around 785 g/eq.
ARADUR 423 XW 60 therefore requires less wet hardener than ARADUR 424 XW 50 for comparable epoxy functionality.
ARADUR 424 XW 50 provides even broader humidity tolerance, with tack-free cure reported up to approximately 100% relative humidity.
ARADUR 423 XW 60 provides a middle balance between concentration, viscosity, reactivity and humidity resistance.
Product choice should therefore reflect the actual environmental conditions and formulation target rather than simply selecting the highest humidity tolerance.

RELATIVE REACTIVITY

The ARADUR 422 XW 70 / 423 XW 60 / 424 XW 50 family provides a progression in concentration, reactivity and humidity tolerance.
ARADUR 422 XW 70 is the more concentrated and more reactive member.
ARADUR 423 XW 60 occupies the intermediate position.
ARADUR 424 XW 50 is the more dilute and more humidity-tolerant member.
Lower reactivity can be beneficial where more working time is required, while higher reactivity can shorten cure time.
The final resin system and ambient temperature strongly influence the practical difference.

POT LIFE

Pot life is the period during which the mixed resin-hardener system remains suitable for application.
ARADUR 423 XW 60 reactivity depends on resin type, temperature, solvent level, pigments and batch size.
Warm conditions shorten pot life because the epoxy-amine reaction accelerates.
Large mixed masses can retain reaction heat and react faster than thin films.
The final formulation should establish practical pot life through viscosity, application quality and cured-film properties rather than relying only on a generic number.

EXOTHERM CONTROL

Epoxy-amine cure is exothermic.
Large batches can accumulate heat, which accelerates the reaction and can shorten working time.
Solvent-containing coating systems are less concentrated in reactive material than neat casting systems, but exotherm still deserves consideration in large mixed quantities.
Smaller batch size and controlled component temperature can reduce the risk of rapid self-heating.
Mixed resin and hardener should not be left reacting unattended in a closed container.

SOLVENT EVAPORATION

Xylene and n-butanol must evaporate during film formation.
If solvent evaporation is too slow, the coating can remain soft and may trap solvent.
If evaporation is too fast, leveling can deteriorate and the film can develop texture or pinholes.
Temperature, ventilation, film thickness and the resin-side solvent package all influence the evaporation profile.
The original hardener solvent balance therefore forms part of the overall coating design.
Additional solvent should be selected with attention to both solvency and evaporation rate.

VENTILATION

Ventilation is essential for both worker safety and coating performance.
Air movement removes xylene and n-butanol vapor from the coating surface and prevents local saturation.
Poor ventilation can extend dry time and increase inhalation exposure.
Excessive airflow can produce dry spray during spray application or reduce leveling.
Ventilation should therefore be controlled rather than simply maximized.
Confined spaces require dedicated solvent-vapor management and appropriate atmospheric safety procedures.

LOW-TEMPERATURE APPLICATION

Cold conditions increase viscosity, slow solvent evaporation and reduce chemical reaction rate.
The pre-adduct structure improves cold-cure reliability but does not eliminate temperature dependence.
The full coating system should be qualified at the minimum intended substrate temperature.
Cold steel or concrete can also fall below the dew point.
Condensation can cause adhesion failure, haze and surface defects even when the curing agent itself has strong humidity resistance.
Substrate temperature and dew-point margin should therefore be monitored during field application.

HIGH-HUMIDITY APPLICATION

ARADUR 423 XW 60 is suitable for tack-free cure at relative atmospheric humidity levels up to approximately 80%.
This makes it particularly useful in marine, construction and maintenance environments.
The humidity capability applies to atmospheric conditions, not to surfaces carrying visible condensation or standing water.
The substrate should still remain dry enough for the coating specification and safely above the dew point.
Ventilation should continue to remove solvent vapor and moisture from the work area.
For conditions consistently above the 80% range, a curing-agent system specifically designed for higher humidity may be preferable.

SURFACE PREPARATION

Surface preparation is essential to adhesion and corrosion protection.
Steel should be free from oil, grease, soluble salts, rust and loose mill scale.
Abrasive blasting is commonly preferred for demanding service because it provides both cleanliness and surface profile.
Mineral substrates should be sound and free from weak laitance, dust, curing compounds and contamination.
Salt-contaminated marine steel should be washed and verified before coating.
No curing-agent chemistry can fully compensate for a contaminated or mechanically weak substrate.

FLASH RUST AND EARLY CORROSION

Solvent-borne coatings are generally less prone to water-driven flash rust than waterborne primers.
Early corrosion can still occur if condensation forms or soluble salts remain on steel.
Thin areas, pinholes and coating holidays can expose the substrate before adequate barrier protection develops.
Environmental control and surface preparation are therefore essential.
Anti-corrosive pigments can provide additional protection but should not be used as a substitute for proper surface preparation.

ANTI-CORROSIVE PIGMENTS

ARADUR 423 XW 60 can be formulated with compatible corrosion-inhibitive pigments and barrier extenders.
Zinc phosphate and related pigments can provide inhibition at coating defects.
Lamellar fillers such as mica or micaceous iron oxide can increase the diffusion path for water and oxygen.
Metallic zinc can provide sacrificial protection in properly designed zinc-rich primers.
Pigment loading should be optimized so that protective function is gained without making the binder film excessively porous.

ZINC-RICH PRIMERS

Zinc-rich primers require high metallic-zinc loading and sufficient electrical contact between zinc particles.
The epoxy binder must hold the pigment in place without isolating the particles excessively.
ARADUR 423 XW 60 can be used in compatible zinc-primer technology where storage stability and gas evolution have been validated.
The relatively low hardener viscosity can simplify incorporation into highly pigmented systems.
Rheology control is important because dense zinc particles settle rapidly if the formulation lacks structure.
Corrosion testing should confirm sacrificial performance and adhesion.

PIGMENT DISPERSION

Uniform pigment dispersion is required for consistent color, rheology and protective performance.
High-shear pigment grinding is generally carried out before final hardener addition to avoid prolonged processing of the fully reactive system.
Pigment surfaces can adsorb resin or amine and can change viscosity after let-down.
The complete formulation should therefore be checked after ARADUR 423 XW 60 is added.
Flocculation can reduce barrier performance and alter settling behavior.
Dispersant selection should be compatible with both the resin and polyamidoamine-adduct hardener.

FILLERS

Mineral fillers can be used to control cost, viscosity, hardness and permeability.
Barytes, talc, calcium carbonate, silica and mica are common filler classes in protective coatings.
Lamellar fillers improve barrier performance by making moisture and oxygen travel through a more tortuous path.
High filler loading can increase viscosity and reduce binder continuity.
Moisture and soluble salts carried by fillers should be controlled because they can influence corrosion and cure.
The filler package should be matched to intended film thickness and application method.

RHEOLOGY CONTROL

Protective primers require enough low-shear structure to prevent pigment settlement and sag.
At application shear, the coating should become sufficiently fluid for spray, brush or roller use.
Fumed silica, organoclays and polymeric rheology modifiers can be used where compatible with the solvent system.
ARADUR 423 XW 60's low viscosity gives the formulator useful flexibility in building rheology through pigments and additives.
Excessive thixotropy can reduce the product's flow advantage and produce poor leveling.
Rheology should be checked throughout pot life because reaction progress can change viscosity.

FLOW AND LEVELING

Flow and leveling influence both appearance and protective uniformity.
ARADUR 423 XW 60 is specifically associated with improved flow.
The low hardener viscosity and solvent balance help the mixed coating level after application.
Good leveling reduces local thin spots and improves continuity of the protective barrier.
Too-fast solvent evaporation can freeze application texture into the film.
Too-slow evaporation can delay hardness.
Solvent balance, application temperature and film thickness should therefore be optimized together.

ADHESION

Polyamidoamine-based curing agents are valued for strong adhesion to properly prepared substrates.
The pre-adduct structure maintains this advantage while improving surface cure.
Higher hardener level within the validated adjustment range tends to increase adhesion.
Metal adhesion depends strongly on removal of oil, salts and corrosion products.
Concrete adhesion depends on substrate strength and removal of laitance.
Adhesion testing after cure and environmental exposure provides a more meaningful measure than initial dry-film appearance alone.

FLEXIBILITY

Higher hardener proportion within the validated range tends to increase flexibility.
Flexible coatings can tolerate impact, vibration and substrate movement more effectively than extremely rigid films.
Polyamidoamine molecular structures contain flexible segments that can reduce brittleness compared with some low-molecular-weight amine hardeners.
Excessive hardener can reduce chemical resistance or hardness, so the optimum ratio depends on service requirements.
Mandrel-bend, impact or other mechanical tests can be used to quantify performance.

CHEMICAL RESISTANCE

Reducing the hardener proportion within the validated formulation range tends to improve chemical resistance.
This change moves the cured network toward a more epoxy-rich composition.
Final chemical resistance depends on the epoxy resin, cure state, film thickness, solvent release and exposure conditions.
A coating that resists intermittent splash may not be suitable for continuous immersion.
Testing should use the actual chemical concentration and temperature expected in service.
Full cure should be achieved before meaningful resistance testing begins.

WATER RESISTANCE

Properly cured epoxy coatings can provide strong water resistance.
Residual solvent and incomplete cure can reduce early water resistance.
Polyamidoamine-adduct systems can maintain good adhesion in humid service when formulation and cure are appropriate.
Continuous immersion should be qualified separately from atmospheric humidity.
The coating should also be checked for blistering and loss of adhesion after wet exposure.

RECOATABILITY

Protective systems commonly require several coats.
The next layer should be applied within a validated recoat interval whenever possible.
Chemical bonding is strongest while the underlying epoxy still retains some reactive functionality.
After full cure, abrasion may be needed to create mechanical profile.
Blush, dust, salts or other contaminants should be removed before recoating.
Residual solvent in thick underlying films should also be allowed to escape before overcoating.

AMINE BLUSH

Amine blush can form when amine curing agents react with atmospheric moisture and carbon dioxide.
The pre-adducted chemistry of ARADUR 423 XW 60 improves humidity resistance and reduces surface tack, but the fundamental blush mechanism can still occur under severe conditions.
Blush can interfere with gloss and intercoat adhesion.
Any visible or suspected surface deposit should be cleaned before recoating.
Environmental control remains important even with a humidity-resistant curing agent.

WEATHERING

Epoxy coatings provide strong adhesion, barrier performance and chemical resistance but can chalk and lose gloss under prolonged ultraviolet exposure.
ARADUR 423 XW 60 is primarily a protective primer and industrial hardener rather than a dedicated long-term exterior decorative finish.
For demanding color and gloss retention, an epoxy primer or intermediate layer is commonly protected with a polyurethane, acrylic or polysiloxane topcoat.
Weathering performance belongs to the complete coating system.
Marine and construction coatings should therefore be designed around both corrosion protection and sunlight exposure.

QUALITY CONTROL

Important quality-control parameters include appearance, Gardner color, solids content, viscosity, amine value and density.
Solids content confirms active hardener concentration and solvent level.
Viscosity provides information about handling consistency and can reveal solvent loss.
Amine value provides a chemical measure of curing-agent functionality.
Density offers a useful secondary physical check.
Functional coating tests can confirm tack-free cure and humidity performance when these properties are critical.

WHY SOLIDS CONTENT MATTERS

Solids content determines the amount of reactive hardener delivered by each kilogram of commercial product.
At lower solids, the same wet weight contributes more solvent and less active curing material.
At higher solids, reactive concentration and viscosity rise.
These changes affect stoichiometry, VOC, drying and final film properties.
The specified 59-61% range should therefore be maintained consistently.
Mix-ratio calculations should use the commercial product as supplied unless a validated dry-solids calculation is being performed.

WHY AHEW MATTERS

AHEW links hardener mass directly to reactive amine hydrogen.
ARADUR 423 XW 60 has an approximate AHEW of 520 g/eq as supplied.
Using an AHEW from another polyamidoamine grade would create a stoichiometric error.
The resin EEW must also be known for theoretical calculation.
Published resin-specific mix ratios provide the best practical starting point where available.
Any intentional deviation should be supported by coating-performance testing.

WHY VISCOSITY MATTERS

The approximately 800-1,400 mPa·s viscosity range is central to the product's easy handling.
Low viscosity simplifies pumping, metering and mixing.
Unexpectedly high viscosity can indicate cold temperature or solvent loss.
Unexpectedly low viscosity can indicate dilution or contamination.
Viscosity should therefore be evaluated together with solids and density.
The sample should be conditioned to the defined test temperature before comparison.

TDS, SDS AND COA

The current Technical Data Sheet should be used for present product properties, resin compatibility, mix-ratio guidance, storage conditions and application recommendations.
The Safety Data Sheet governs formal component disclosure, flammability, occupational controls, first aid, transport and disposal.
The Certificate of Analysis provides batch-specific controlled values where supplied.
Historical selector documents can provide useful comparative formulation data, but current product documents should control regulatory and specification decisions.

SAFETY AND HANDLING

ARADUR 423 XW 60 is a reactive amine-containing hardener dissolved in flammable organic solvent and should be handled according to the current SDS.
Chemical-resistant gloves, eye protection and suitable protective clothing should be used.
Good ventilation is essential because xylene and n-butanol vapors can accumulate in enclosed spaces.
Ignition sources should be controlled because the product has a relatively low flash point.
Spray application increases inhalation exposure through both solvent vapor and coating aerosol.
Industrial hygiene procedures should cover mixing, transfer, spray application and cleanup.

SKIN CONTACT

Direct skin contact should be avoided.
Reactive amine components can irritate skin and may contribute to sensitization.
Organic solvents can remove natural skin oils and increase irritation.
Contaminated skin should be washed promptly according to the current SDS.
Solvents should not be used for skin cleaning.
Contaminated clothing should be removed and cleaned or disposed of appropriately.

EYE CONTACT

Eye protection is essential during pouring, pumping, mixing and spraying.
If product enters the eyes, immediate prolonged rinsing with clean water should begin.
Medical attention should be obtained according to SDS guidance.
Emergency eyewash equipment should be available in routine handling areas.
Contact lenses should never delay immediate flushing.

INHALATION

Xylene and n-butanol create vapor exposure potential in poorly ventilated areas.
Spray application also produces aerosol.
Local exhaust ventilation and general ventilation should be designed to keep exposure within applicable occupational limits.
Respiratory protection should be selected according to workplace risk assessment and the current SDS.
Confined-space coating requires especially careful atmospheric control.

INGESTION

ARADUR 423 XW 60 is an industrial product and must not be ingested.
Food and beverages should be excluded from formulation and application areas.
After accidental ingestion, current SDS instructions and medical advice should be followed.
Because the material contains volatile organic solvent, inappropriate first-aid actions can create additional aspiration risk.

SPILL MANAGEMENT

A spill can spread quickly because the product is a relatively low-viscosity solvent-containing liquid.
Ignition sources should be removed where safe to do so.
The area should be ventilated.
Personnel should use suitable PPE specified in the current SDS.
Compatible absorbent can be used for small spills, while larger releases may require pumping and specialized response.
Discharge to drains, soil and surface water should be prevented.

FIRE RESPONSE

The approximately 28°C flash point requires strict fire precautions.
Xylene/n-butanol vapor can form flammable mixtures with air.
Combustion and thermal decomposition can generate carbon oxides, nitrogen oxides and other hazardous fumes.
Firefighters may require self-contained breathing apparatus and chemical-resistant protective equipment.
Extinguishing media and emergency response should follow the current SDS and site fire plan.

STORAGE

ARADUR 423 XW 60 should be stored in a dry place, preferably in the sealed original container, at approximately 2-40°C.
The product should be protected from direct sunlight.
Containers should remain tightly closed to minimize solvent loss and contamination.
Storage areas should be suitable for flammable liquids and should control ignition sources.
Material should be conditioned to an appropriate processing temperature before metering.
The expiry date on the original package and current technical documentation should control shelf-life decisions.

REGULATORY CONSIDERATIONS

ARADUR 423 XW 60 is a proprietary industrial mixture containing reactive polyamidoamine-adduct material and volatile organic solvents.
VOC, flammable-liquid, transport and worker-exposure requirements vary by jurisdiction.
Generic use in anti-corrosion, marine or construction coatings does not establish approval for food contact, potable water, medical devices or other specialized regulated uses.
Current chemical-inventory and regulatory declarations should be obtained from current product documentation when needed.
Finished-coating compliance must be assessed for the complete formulation rather than for the hardener alone.

ENVIRONMENTAL CONSIDERATIONS

The xylene/n-butanol solvent package contributes volatile organic emissions during coating application and drying.
Uncured hardener and mixed epoxy should not be released directly to soil, drains or surface water.
Cleaning solvent, contaminated absorbent and leftover mixed coating should be managed under applicable waste rules.
High-solids resin technology and optimized solvent level can reduce total VOC, but reformulation must preserve compatibility and film formation.
Fully cured epoxy has very different mobility and reactivity from the uncured components, but disposal requirements remain jurisdiction-specific.

COMMON FORMULATION PROBLEMS

Persistent surface tack
Low temperature, excessive humidity, incorrect mix ratio or poor solvent release can delay surface cure. Confirm environmental conditions and remain within the validated formulation window.

Whitening or haze
Humidity, condensation or incompatible formulation components can create surface haze. Keep the substrate safely above the dew point and within the intended humidity limit.

Poor flow
Excessive viscosity, fast solvent evaporation or excessive thixotrope can reduce leveling. Rebalance solvent and rheology within validated formulation limits.

Sagging
Too much solvent or insufficient low-shear structure can cause vertical sag. Adjust rheology and wet-film thickness.

Short pot life
Warm materials, large batch size or highly reactive resin can accelerate cure. Standardize component temperature and batch size.

Slow cure
Cold conditions, incorrect stoichiometry or excess solvent can delay cure. Verify ratio, temperature and film conditions.

Poor adhesion
Oil, salts, rust, weak concrete laitance or condensation can prevent bonding. Correct surface preparation before changing chemistry.

Poor corrosion resistance
Low film thickness, pinholes, poor steel preparation or weak anti-corrosive pigment design can reduce protection. Evaluate the complete system.

Poor zinc-primer performance
Incorrect zinc loading, weak particle connectivity, binder excess or poor substrate preparation can reduce sacrificial protection. Validate zinc concentration and electrical continuity.

Soft film
Residual solvent, excessive hardener or incomplete cure can leave the coating soft. Allow adequate solvent evaporation and confirm stoichiometry.

Low chemical resistance
Excess hardener or incomplete cure can reduce resistance. Consider the validated lower-hardener side of the formulation range and confirm full cure.

Brittleness
Too little hardener or a highly rigid resin can produce a brittle film. Adjust within the validated ratio range and evaluate flexibility.

Blistering
Entrapped solvent, moisture contamination or osmotic effects from soluble salts can create blisters. Improve drying, surface preparation and film design.

Intercoat adhesion failure
Overcure, blush or surface contamination can interfere with the next coat. Observe the recoat window and prepare the surface when required.

Solvent popping
Rapid surface closure can trap volatile solvent and create pinholes or craters. Control film thickness, solvent evaporation and drying temperature.

FREQUENTLY ASKED QUESTIONS

What is ARADUR 423 XW 60?
ARADUR 423 XW 60 is a solvent-borne polyamidoamine-adduct epoxy curing agent supplied in a xylene/n-butanol solvent blend.

What is the solvent blend?
The commercial grade is described as a polyamidoamine adduct in xylene/n-butanol at an approximate 4:1 ratio.

What is the solids content?
Approximately 59-61%.

What is the viscosity?
Approximately 800-1,400 mPa·s at 25°C.

What is the amine value?
Approximately 122-138 mg KOH/g.

What is the active hydrogen equivalent weight?
Approximately 520 g/eq as supplied.

What is the density?
Approximately 0.94 g/cm³ at 20°C.

What is the Gardner color?
Approximately ≤10.

What is the flash point?
Approximately 28°C by closed-cup testing.

What humidity level is supported?
Technical guidance identifies tack-free cure at up to approximately 80% relative atmospheric humidity.

What are the main product benefits?
Improved humidity resistance, improved flow, reduced surface tack and reliable tack-free cure under cold-damp conditions.

What is the reference ratio with ARALDITE GZ 7071 X 75?
Approximately 100 parts resin to 82 parts ARADUR 423 XW 60 by weight.

Can the mix ratio be adjusted?
Yes. The reference system allows deviations of approximately ±15% depending on target film properties.

What happens if more hardener is used?
Within the validated adjustment range, a higher hardener proportion generally improves flexibility and adhesion.

What happens if less hardener is used?
Within the validated adjustment range, a lower hardener proportion generally improves chemical resistance.

What is the typical selector ratio?
Comparative selector literature gives approximately 110 parts ARADUR 423 XW 60 per 100 parts of the reference resin used in that selector.

What epoxy resins are suitable?
Liquid epoxy resins and, preferably, solid epoxy resins or their solutions can be used when compatibility and stoichiometry are appropriate.

What are the main applications?
Anti-corrosion coatings, cold-curing coatings, marine finishes, shipbuilding coatings, construction coatings and industrial maintenance systems.

Can ARADUR 423 XW 60 be used on steel?
Yes. Steel is a primary substrate.

Can it be used on mineral substrates?
Yes. Compatible solvent-borne epoxy systems can be formulated for mineral substrates.

How does ARADUR 423 XW 60 compare with ARADUR 422 XW 70?
ARADUR 423 XW 60 has lower solids and viscosity, higher AHEW and higher humidity tolerance.

How does ARADUR 423 XW 60 compare with ARADUR 424 XW 50?
ARADUR 423 XW 60 is more concentrated and generally more reactive, while ARADUR 424 XW 50 provides even broader humidity tolerance.

Is ARADUR 423 XW 60 flammable?
Yes. The xylene/n-butanol solvent package gives the commercial product a relatively low flash point, so flammable-liquid precautions are required.

Does ARADUR 423 XW 60 have one CAS number?
No. The complete commercial grade is a formulated mixture and should not be assigned one CAS number without confirmation from the current SDS.

How should ARADUR 423 XW 60 be stored?
Store dry in the sealed original container at approximately 2-40°C, protect from direct sunlight and follow current flammable-liquid storage requirements.

What documents should be checked before use?
Use the current product TDS, SDS and batch-specific quality documentation where available.

FINAL TECHNICAL SUMMARY

ARADUR 423 XW 60 is a solvent-borne polyamidoamine-adduct curing agent designed for cold-curing epoxy coatings on steel and mineral substrates.
The commercial grade is supplied at approximately 59-61% solids in a xylene/n-butanol solvent blend at an approximate 4:1 ratio.
Published technical data specify approximately 800-1,400 mPa·s viscosity at 25°C, 122-138 mg KOH/g amine value, about 520 g/eq active-hydrogen equivalent weight, approximately 0.94 g/cm³ density and Gardner color no higher than approximately 10.
The product combines traditional polyamidoamine adhesion and flexibility with pre-adduct technology that improves humidity resistance, reduces surface tack and improves flow.

ARADUR 423 XW 60 is suitable for tack-free cure at relative atmospheric humidity levels up to approximately 80% when substrate and environmental conditions are otherwise appropriate.
This humidity tolerance is broader than that of ARADUR 422 XW 70 and lower than that of ARADUR 424 XW 50, placing ARADUR 423 XW 60 in the middle of the family for concentration, reactivity and cold-damp performance.
Anti-corrosion coatings, cold-curing coatings, marine finishes, shipbuilding systems, construction coatings and industrial maintenance are important application areas.

The grade can be combined with compatible liquid epoxy resins and, preferably, solid epoxy resins or their solutions.
ARALDITE GZ 7071 X 75 is an important reference resin system. The reference mix ratio is approximately 100 parts resin to 82 parts ARADUR 423 XW 60 by weight.
The reference ratio can be adjusted by approximately ±15% depending on desired properties. More hardener generally favors flexibility and adhesion, while less hardener generally favors chemical resistance.
Comparative selector literature also gives a typical ratio around 110 parts hardener per 100 parts of its reference resin. This different value reflects use of a different resin system and should not be transferred to GZ 7071 X 75.

The xylene/n-butanol carrier system provides low viscosity and good solvency but also gives the commercial hardener a relatively low flash point of about 28°C. Ventilation and ignition control are therefore essential.
Surface preparation remains central to corrosion performance. Steel should be clean, salt-free and appropriately profiled, while mineral substrates should be sound and free from weak laitance and contamination.

Anti-corrosive pigments, zinc-rich technology and barrier fillers can be incorporated where compatibility and storage stability are validated.
Quality control should focus on solids content, viscosity, amine value, density, color, appearance and functional cure behavior.
ARADUR 423 XW 60 is a proprietary commercial mixture and should not be assigned an invented single molecular formula, molecular weight, CAS number or EC number. Current product-specific SDS documentation should control formal identity and hazard classification.
For ARADUR 423 XW 60 technical specifications, application guidance, TDS, SDS, COA and formulation information, contact Ataman Chemicals with the intended epoxy resin, substrate, pigment package, application conditions and required protective performance.

Ataman Chemicals
Phone: +90 216 577 10 10
Email: info@atamankimya.com