CAS 32435-46-4: KM2120 Difunctional Phosphate Ester

Bottom line: CAS 32435-46-4 identifies bis(2-methacryloxyethyl) phosphate, supplied by JCCM as KM2120. It contains two polymerisable methacrylate ends and is positioned for difunctional crosslinking, low colour and higher network strength compared with HEMAP.

What CAS 32435-46-4 identifies

The substance contains two methacrylate double bonds and a polar phosphate region. Its EINECS number is 251-040-2. The difunctional structure can participate more densely in the cured network, while the phosphate end can still interact with metals, glass, ceramics and selected inorganic fillers.

Positioning of KM2120

KM2120 is a low-colour difunctional phosphate ester for evaluation in light or clear UV systems, solder-resist inks, vacuum metallising, optical adhesives and electronic adhesives. Difunctionality can improve solvent resistance and network strength but may increase shrinkage, so the balance must be tested in the target formula.

• Chemical name: bis(2-methacryloxyethyl) phosphate
• CAS: 32435-46-4; EINECS: 251-040-2
• JCCM grade: KM2120
• Search aliases: difunctional phosphate methacrylate, bis HEMA phosphate, phosphate diacrylate monomer

Difference from CAS 52628-03-2

CAS 52628-03-2 corresponds to HEMAP/KM2110, commonly a monofunctional methacrylate phosphate. CAS 32435-46-4 corresponds to KM2120, which has two methacrylate ends. They should not be interchanged merely because both are phosphate esters. Compare functionality, acid value, colour, viscosity, shrinkage, adhesion and storage stability.

Procurement and application validation

• Confirm CAS, EINECS, chemical name, functionality and batch COA.
• Check colour, acid value, free acid, water, viscosity and inhibitor.
• For light or optical systems, assess yellowing, haze, transmittance and ionic impurities.
• Compare monofunctional and difunctional grades in the target resin to balance crosslinking, shrinkage and flexibility.
• Dental, medical, cosmetic and food-contact uses require separate grade and regulatory approval.

Frequently asked questions

Are CAS 32435-46-4 and KM2120 the same thing?

The CAS number identifies the substance, while KM2120 is a specific commercial grade. A purchase specification should include both substance identity and grade properties.

Does difunctionality always give better adhesion than HEMAP?

No. Higher functionality may improve network density and solvent resistance, but adhesion also depends on acid value, interfacial concentration, substrate, cure and stress. Test both in the same formulation rather than inferring performance from functionality alone.