MOCA / MBOCA
4,4'-Methylenebis(2-chloroaniline) — sold industry-wide under the names MOCA and MBOCA — supplied by Chelora Chemicals as the standard curing agent for cast polyurethane elastomers and a widely used epoxy hardener, exported from Indonesia as flake or pellet with full batch documentation on every shipment.
What MOCA / MBOCA is, and why buyers source it
A working overview of the compound's chemistry, its role as the industry-standard curative for cast polyurethane elastomers, and the grade Chelora Chemicals keeps in regular supply.
MOCA / MBOCA — 4,4'-methylenebis(2-chloroaniline) — is a chlorinated aromatic diamine: the same methylene-bridged diphenylamine skeleton as 4,4'-methylenedianiline, but with a chlorine substituent ortho to each primary amine. That chlorine sterically and electronically moderates the reactivity of the amine groups, slowing their reaction with isocyanate-terminated prepolymers just enough to give processors a workable pot life while still curing to a tough, high-performance elastomer.
At room temperature it is a tan to light brown solid supplied as flake or pellet, which is melted to a low-viscosity amber liquid for metered dosing into prepolymer systems. It is used industry-wide as a curing agent (chain extender) for millable and castable polyurethane elastomer systems, and separately as a curing agent for certain epoxy resin formulations.
Where it fits in the value chain
MOCA / MBOCA's dominant end use, by far, is as the curing agent (chain extender) for cast polyurethane elastomer systems: it is melted and metered into an isocyanate-terminated polyurethane prepolymer, where its two moderated primary amines react to extend and crosslink the polymer chain, building the hardness, abrasion resistance and load-bearing properties that polyurethane rollers, wheels, seals and industrial linings are valued for. It is also used, less commonly, as a curing agent for epoxy resin systems where a slower, more controllable cure than an aliphatic amine is wanted.
Grade we supply
Chelora Chemicals offers MOCA / MBOCA in curing-agent grade (99.5%+ assay) as flake or pellet, suited to cast polyurethane elastomer processing and epoxy curing applications. The grade is supplied with a batch-wise certificate of analysis.
How MOCA / MBOCA is made
An overview of the production route for orientation purposes. Our manufacturing partners' own process parameters and in-process controls are proprietary and are not disclosed beyond what is needed to interpret the certificate of analysis.
MOCA / MBOCA is manufactured by the acid-catalysed condensation of ortho-chloroaniline with formaldehyde, in a molar ratio of roughly two moles of chloroaniline per mole of formaldehyde, under strong acid catalysis: 2 ClC₆H₄NH₂ + HCHO → CH₂(C₆H₃ClNH₂)₂ + H₂O. The reaction is directly analogous to the aniline-formaldehyde route to 4,4'-methylenedianiline, with the ortho-chlorine already present on the starting aniline carried through into the product.
After neutralisation, the crude product is purified by crystallisation and, where required, distillation to the required assay, colour and melting-point specification before flaking or pelletising and packing.
Industries and processes that use it
MOCA / MBOCA is consumed overwhelmingly by cast polyurethane elastomer processing, with established secondary demand from epoxy curing. The fields below account for most of the demand we see through our export desk.
Cast Polyurethane Elastomer Curative
The industry-standard chain extender for isocyanate-terminated prepolymer systems used to cast industrial rollers, wheels, seals and linings.
Epoxy Resin Curing Agent
Used in select epoxy formulations where a slower, more controllable cure profile than an aliphatic amine curative is wanted.
Polyurethane Tyre & Solid-Wheel Compounds
Extends and crosslinks polyurethane used in solid tyres, forklift wheels and other heavy-duty elastomer components.
Industrial Coatings & Linings
A curative in protective polyurethane coating and lining systems applied for abrasion and chemical resistance.
How the molecule is typically carried forward
The two moderated primary amines, flanked by ortho-chlorine substituents, govern almost all of this molecule's further reaction chemistry. Reaction classes below account for most of the ways MOCA / MBOCA is converted into a finished elastomer or coating.
Chain Extension of PU Prepolymers
Each primary amine reacts with an isocyanate end-group on the prepolymer chain, forming a urea linkage that extends and crosslinks the polyurethane network.
Epoxide Ring-Opening (Curing)
Each of the two primary amines opens an epoxide ring in turn, crosslinking epoxy resin into a thermoset network with a cure rate moderated by the ortho-chlorine.
Controlled Reactivity vs. Unsubstituted Diamines
The ortho-chlorine substituents slow amine-isocyanate reactivity relative to an unsubstituted aromatic diamine, giving processors a workable pot life for casting before gelation.
Post-Cure Network Formation
After initial gelation, continued reaction and physical crosslink development during post-cure build the final hardness and mechanical properties of the elastomer.
MOCA / MBOCA against other aromatic amines we supply
Buyers sourcing this curative for polyurethane elastomer or epoxy chemistry often need the parent diamine or a related aromatic amine. A quick reference to what else is on our regular supply list.
| Product | CAS Number | Category | Notes |
|---|---|---|---|
| MOCA / MBOCA | 101-14-4 | Chlorinated aromatic diamine | The product on this page — the industry-standard curative for cast polyurethane elastomers. |
| 4,4'-Methylenedianiline | 101-77-9 | Aromatic diamine | The unsubstituted parent diamine and principal precursor to MDI — see its product page. |
| Diphenylamine | 122-39-4 | Secondary aromatic amine | A related aromatic amine, feedstock for diphenylamine-type rubber antioxidants — see its product page. |
| Benzene | 71-43-2 | Aromatic hydrocarbon | The upstream feedstock behind aniline, chloroaniline and the wider aromatic-amine family — see its product page. |
Exact physical constants and purity specifications are confirmed per batch on the certificate of analysis — treat the notes above as a sourcing guide, not a specification sheet, for products other than MOCA / MBOCA.
Safety classification at a glance
Based on GHS classification as commonly listed for this substance. This is a summary for orientation only — always work from the current safety data sheet supplied with your specific batch.
May cause cancer.
Suspected of causing genetic defects.
Toxic if swallowed.
Toxic in contact with skin.
Causes damage to organs through prolonged or repeated exposure.
Very toxic to aquatic life.
Very toxic to aquatic life with long lasting effects.
Danger — GHS08 health hazard, GHS06 toxic and GHS09 environmental hazard pictograms apply.
This compound is classified as a suspected human carcinogen and mutagen, is toxic if swallowed and in contact with skin, and causes organ damage through prolonged or repeated exposure. It is subject to strict occupational exposure controls in most jurisdictions, including dedicated handling areas, medical surveillance and closed or local-exhaust-ventilated dosing systems in many facilities. It must be handled strictly under the controls set out in the MSDS issued with every shipment, which should be read in full, together with applicable local occupational exposure regulations, before this material is handled.
Keeping it on spec between delivery and use
General storage guidance for this grade. Site-specific storage rules, segregation requirements and re-test intervals should follow your own EHS procedures and the MSDS issued with your batch.
Store in a cool, dry, segregated area away from strong oxidising agents and strong acids, in tightly closed original packaging, protected from moisture. Given its occupational health classification, storage and handling areas should follow dedicated segregation and access-control procedures in line with local regulations and the MSDS. If a batch is held past its retest date, re-check assay, colour and melting point before use.
How it ships from Indonesia
Standard packing and export terms for this product. Confirm exact figures against your order — they vary slightly by destination and quantity.
What travels with every batch
Specification is agreed before the purchase order, not discovered on arrival. Every shipment of MOCA / MBOCA leaves with a documented, checkable paper trail.
Certificate of Analysis
Batch-wise assay, colour and key physical constants, issued against the agreed specification so your QC team can check it, not just file it.
Safety Data Sheet
GHS-format SDS in English covering hazard classification, handling, storage, first-aid and spill response for the exact grade shipped.
Technical Data Sheet
Reference physical and chemical properties, recommended storage and typical applications, for internal circulation to your process or R&D teams.
Certificate of Origin
Confirms Indonesian origin for customs clearance and any preferential-duty claim at your destination port.
Dangerous Goods Declaration
UN packing group, classification and shipper's declaration prepared ahead of loading so documentation never holds up customs.
Third-Party Inspection
Independent pre-shipment inspection and re-sampling can be arranged on request, at your cost, for buyers who require it as a matter of policy.
Frequently asked questions
What buyers most often ask our sales desk about this grade.
01What is MOCA / MBOCA used for?+
02What is the CAS number of MOCA / MBOCA?+
03How is MOCA / MBOCA made?+
04What purity grade does Chelora Chemicals supply?+
05Is MOCA / MBOCA hazardous?+
06Why does polyurethane casting need this chlorinated diamine rather than the unsubstituted diamine?+
07What packing options are available?+
08How long does delivery take?+
09Can I get a sample before placing a bulk order?+
10Do you supply other aromatic amines as well?+
Need MOCA / MBOCA on spec, on time?
Send us your required purity, quantity, packing preference and destination port. Our desk quotes most enquiries within one working day.