Sealed red steel drums of specialty diisocyanate on pallets in a warehouse

XDI Xylylene Diisocyanate

Name: XDI Xylylene Diisocyanate
Brand: KingZhi Chemistry

Optical grade diisocyanate with aliphatic behaviour and aromatic economics

Overview

What This Product Is and Who Buys It

XDI is a colourless to pale yellow clear liquid diisocyanate whose NCO groups attach to an aromatic ring through methylene bridges. That structure makes it behave like an aliphatic material: outstanding non yellowing performance, optical clarity and weather resistance, which is why it is the standard choice for high refractive index optical lens resins.

Key Benefits

Exceptional non yellowing performance and optical transparency
High refractive index polyurethane resins for eyeglass lenses
Very low viscosity at approximately 3 to 5 mPa·s at 25°C
NCO content of approximately 44.6 to 44.8 percent, high for a light stable grade

Applications

Where This Material Is Used

Optical lenses including high refractive index eyeglass lensesNon yellowing clear coatings and inksHigh performance adhesives and sealantsSpecialty coatings for electronics and automotiveTransparent elastomers and films

Who It Is For

Optical lens resin manufacturers
Clear coating and ink formulators
Electronics encapsulation and specialty coating producers
Transparent elastomer and film makers

Problems It Solves

Lens resins that need both high refractive index and long term clarity
Clear coatings where any amber cast is a rejection
Systems needing low viscosity without solvent dilution

Technical

Technical Features

Colourless to pale yellow clear liquid
Molecular formula C10H8N2O2, molecular weight 188.2 g/mol
NCO groups attached via methylene bridges, giving aliphatic like behaviour
Freezing point approximately -7°C, remains liquid in normal storage

Specifications

These figures are the manufacturer grade data as published for this product family. Anything not listed below has not been confirmed and is marked TBC on request rather than estimated.

Property	Specification
Appearance	Colourless to pale yellow clear liquid
NCO Content (%)	≈ 44.6 - 44.8
Purity (%)	≥ 99.0 typical commercial grade
Viscosity at 25°C	≈ 3 - 5 mPa·s
Freezing Point	≈ -7°C
Density at 25°C	≈ 1.18 g/cm³
Molecular Weight	188.2 g/mol

Grades listed are representative and not exhaustive. Ask for the batch certificate of analysis on the grade you intend to buy.

Comparison

How It Compares

Within the Isocyanates category this product is positioned by the numbers in the table above rather than by a marketing claim. Compare NCO content, viscosity, equivalent weight or hydroxyl value against the alternative you are considering, and if the two are close, ask us for both samples and decide on your own line.

Quality and Documentation

Quality control runs across incoming raw materials, production and finished product inspection. A batch certificate of analysis is supplied with every shipment. We are a supply and trading company working with named manufacturers and OEM partners, so certification held by the producing plant is provided on request per grade rather than claimed here as ours.

Customisation

Customised grades and packing formats are available through our OEM partners and specialised manufacturing facilities. Tell us the property you need to move and we will say whether it is a grade change, a packaging change or not possible.

FAQ

XDI Questions

Is XDI aromatic or aliphatic?

Structurally it has an aromatic ring, but the NCO groups are not attached to it directly. They sit on methylene bridges, so the material behaves like an aliphatic isocyanate and does not yellow.

Why is XDI used for optical lenses?

It gives a high refractive index polyurethane resin that stays transparent and does not develop a colour cast. That combination is difficult to achieve with conventional aliphatic chemistry.

How low is the viscosity really?

Approximately 3 to 5 mPa·s at 25 degrees C, which is thin enough to formulate without added solvent in many systems.

Can XDI be used to make polyisocyanates?

Yes. It is used both as a direct component and as a feedstock for synthesising polyisocyanates for 2K coatings, adhesives and elastomers.